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A086631 Antidiagonal sums of square table A086629. 5
1, 2, 4, 10, 29, 92, 310, 1088, 3931, 14518, 54551, 207856, 801202, 3118532, 12239732, 48385852, 192483953, 769974110, 3095236066, 12497442266, 50660112478, 206093561590, 841151382755, 3443278744832, 14133534466258 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
G.f.: A(x) = 1/(1-x)^2 + x^2*A(x)^3.
a(n) = Sum_{k=0..floor(n/2)} binomial(n+2*k+1,4*k+1) * binomial(3*k,k) / (2*k+1). - Seiichi Manyama, Jul 30 2023
PROG
(PARI) a(n) = sum(k=0, n\2, binomial(n+2*k+1, 4*k+1)*binomial(3*k, k)/(2*k+1)); \\ Seiichi Manyama, Jul 30 2023
CROSSREFS
Cf. A001764, A086615, A086629 (table), A086630 (diagonal).
Sequence in context: A182486 A000995 A010359 * A320903 A230957 A279552
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 24 2003
STATUS
approved

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Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)