A129653 Antidiagonal sums of number triangle A129652.

1, 1, 4, 15, 83, 556, 4435, 40773, 423836, 4908403, 62606297, 871421976, 13136605577, 213122669141, 3701085673676, 68480774296803, 1344611320542931, 27917413103561540, 611000785570868627, 14056645627856206809, 339081826905338009620, 8557085279980716462407

Offset

0,3

Links

Table of n, a(n) for n=0..21.

T.-X. He, A symbolic operator approach to power series transformation-expansion formulas, JIS 11 (2008) 08.2.7

Formula

a(n) = Sum_{k=0..floor(n/2)} (((n-k)!/k!)*sum{i=0..n-2k} C(n-2k-1,i)/(n-2k-i)!).

Prog

(PARI) a(n) = sum(k=0, n\2, ((n-k)!/k!)*sum(i=0, n-2*k, binomial(n-2*k-1, i)/(n-2*k-i)!)); \\ Michel Marcus, Sep 10 2015

Crossrefs

Cf. A129652.

Sequence in context: A207161 A203121 A232220 * A081722 A117927 A143340

Adjacent sequences: A129650 A129651 A129652 * A129654 A129655 A129656

Keyword

easy,nonn

Author

Paul Barry, Apr 26 2007

Status

approved