|
|
A113408
|
|
Riordan array (1/(1-x^2-x^4*c(x^4)),x*c(x^2)), c(x) the g.f. of A000108.
|
|
2
|
|
|
1, 0, 1, 1, 0, 1, 0, 2, 0, 1, 2, 0, 3, 0, 1, 0, 6, 0, 4, 0, 1, 3, 0, 12, 0, 5, 0, 1, 0, 12, 0, 20, 0, 6, 0, 1, 6, 0, 30, 0, 30, 0, 7, 0, 1, 0, 30, 0, 60, 0, 42, 0, 8, 0, 1, 10, 0, 90, 0, 105, 0, 56, 0, 9, 0, 1, 0, 60, 0, 210, 0, 168, 0, 72, 0, 10, 0, 1, 20, 0, 210, 0, 420, 0, 252, 0, 90, 0, 11, 0, 1
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,8
|
|
COMMENTS
|
Row sums are A113409. Diagonal sums are A005773(n+1) with interpolated zeros.
|
|
LINKS
|
|
|
FORMULA
|
T(n, k) = C((n+k)/2,k)*C(floor((n-k)/2),floor((n-k)/4))(1+(-1)^(n-k))/2.
|
|
EXAMPLE
|
Triangle begins
1;
0,1;
1,0,1;
0,2,0,1;
2,0,3,0,1;
0,6,0,4,0,1;
3,0,12,0,5,0,1;
|
|
MATHEMATICA
|
Table[Binomial[(n + k)/2, k]*Binomial[Floor[(n - k)/2], Floor[(n - k)/4]]*(1 + (-1)^(n - k))/2, {n, 0, 49}, {k, 0, n}] // Flatten (* G. C. Greubel, Mar 09 2017 *)
|
|
PROG
|
(PARI) for(n=0, 25, for(k=0, n, print1( binomial((n+k)/2, k) *binomial(floor((n-k)/2), floor((n-k)/4))*(1+(-1)^(n-k))/2, ", "))) \\ G. C. Greubel, Mar 09 2017
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|