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A225084
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Triangle read by rows: T(n,k) is the number of compositions of n with maximal up-step k; n>=1, 0<=k<n.
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5
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1, 2, 0, 3, 1, 0, 5, 2, 1, 0, 7, 6, 2, 1, 0, 11, 12, 6, 2, 1, 0, 15, 26, 14, 6, 2, 1, 0, 22, 50, 33, 14, 6, 2, 1, 0, 30, 97, 72, 34, 14, 6, 2, 1, 0, 42, 180, 156, 77, 34, 14, 6, 2, 1, 0, 56, 332, 328, 173, 78, 34, 14, 6, 2, 1, 0, 77, 600, 681, 378, 177, 78, 34, 14, 6, 2, 1, 0, 101, 1078, 1393, 818, 393, 178, 78, 34, 14, 6, 2, 1, 0
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OFFSET
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1,2
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COMMENTS
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T(n,k) is the number of compositions [p(1), p(2), ..., p(k)] of n such that max(p(j) - p(j-1)) == k.
The first column is A000041 (partition numbers).
Sum of first and second column is A003116.
Sum of the first three columns is A224959.
The second columns deviates from A054454 after the term 600.
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LINKS
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EXAMPLE
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Triangle starts:
01: 1,
02: 2, 0,
03: 3, 1, 0,
04: 5, 2, 1, 0,
05: 7, 6, 2, 1, 0,
06: 11, 12, 6, 2, 1, 0,
07: 15, 26, 14, 6, 2, 1, 0,
08: 22, 50, 33, 14, 6, 2, 1, 0,
09: 30, 97, 72, 34, 14, 6, 2, 1, 0,
10: 42, 180, 156, 77, 34, 14, 6, 2, 1, 0,
11: 56, 332, 328, 173, 78, 34, 14, 6, 2, 1, 0,
12: 77, 600, 681, 378, 177, 78, 34, 14, 6, 2, 1, 0,
13: 101, 1078, 1393, 818, 393, 178, 78, 34, 14, 6, 2, 1, 0,
14: 135, 1917, 2821, 1746, 863, 397, 178, 78, 34, 14, 6, 2, 1, 0,
15: 176, 3393, 5660, 3695, 1872, 877, 398, 178, 78, 34, 14, 6, 2, 1, 0,
...
The fifth row corresponds to the following statistics:
#: M composition
01: 0 [ 1 1 1 1 1 ]
02: 1 [ 1 1 1 2 ]
03: 1 [ 1 1 2 1 ]
04: 2 [ 1 1 3 ]
05: 1 [ 1 2 1 1 ]
06: 1 [ 1 2 2 ]
07: 2 [ 1 3 1 ]
08: 3 [ 1 4 ]
09: 0 [ 2 1 1 1 ]
10: 1 [ 2 1 2 ]
11: 0 [ 2 2 1 ]
12: 1 [ 2 3 ]
13: 0 [ 3 1 1 ]
14: 0 [ 3 2 ]
15: 0 [ 4 1 ]
16: 0 [ 5 ]
There are 7 compositions with no up-step (M=0), 6 with M=1, 2 with M=2, and 1 with M=3.
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MAPLE
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b:= proc(n, v) option remember; `if`(n=0, 1, add((p->
`if`(i<v, add(coeff(p, x, h)*x^`if`(h<v-i, v-i, h),
h=0..degree(p)), p))(b(n-i, i)), i=1..n))
end:
T:= n-> seq(coeff(b(n, 0), x, i), i=0..n-1):
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MATHEMATICA
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b[n_, v_] := b[n, v] = If[n == 0, 1, Sum[Function[{p}, If[i<v, Sum[Coefficient[p, x, h]*x^If[h<v-i, v-i, h], {h, 0, Exponent[p, x]}], p]][b[n-i, i]], {i, 1, n}]] ; T[n_] := Table[Coefficient[b[n, 0], x, i], {i, 0, n-1}]; Table[T[n], {n, 1, 14}] // Flatten (* Jean-François Alcover, Feb 18 2015, after Alois P. Heinz *)
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CROSSREFS
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Cf. A225085 (partial sums of rows).
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KEYWORD
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AUTHOR
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STATUS
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approved
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