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A131076
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Row sums of triangular array T: T(j,1) = 1 for ((j-1) mod 8) < 4, else 0; T(j,k) = T(j-1,k-1) + T(j,k-1) for 2 <= k <= j.
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4
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1, 3, 7, 15, 26, 42, 64, 93, 139, 231, 463, 1092, 2744, 6840, 16384, 37383, 81295, 169119, 338239, 654192, 1232288, 2280864, 4194304, 7761375, 14635711, 28384383, 56768767, 116566080, 243472256, 511907712, 1073741824, 2232713343
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OFFSET
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1,2
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COMMENTS
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Sum of n-th row equals (n+1)-th term of main diagonal minus (n+1)-th term of first column: a(n) = A129961(n+1) - A131078(n+1).
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LINKS
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FORMULA
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(1-4*x+6*x^2-4*x^3-2*x^4+10*x^5-10*x^6+5*x^7-x^8)/((1-x)*(1-2*x)*(1+x^4)*(1-4*x+6*x^2-4*x^3+2*x^4)).
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EXAMPLE
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PROG
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(Magma) m:=32; M:=ZeroMatrix(IntegerRing(), m, m); for j:=1 to m do if (j-1) mod 8 lt 4 then M[j, 1]:=1; end if; end for; for k:=2 to m do for j:=k to m do M[j, k]:=M[j-1, k-1]+M[j, k-1]; end for; end for; [ &+[ M[j, k]: k in [1..j] ]: j in [1..m] ];
(PARI) {m=32; M=matrix(m, m); for(j=1, m, M[j, 1]=if((j-1)%8<4, 1, 0)); for(k=2, m, for(j=k, m, M[j, k]=M[j-1, k-1]+M[j, k-1])); for(j=1, m, print1(sum(k=1, j, M[j, k]), ", "))}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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