A014784 Triangle of numbers associated with Genocchi numbers.
1, 1, 1, 2, 3, 2, 7, 12, 12, 7, 38, 69, 81, 69, 38, 295, 552, 702, 702, 552, 295, 3098, 5901, 7857, 8559, 7857, 5901, 3098, 42271, 81444, 111618, 128034, 128034, 111618, 81444, 42271, 726734, 1411197, 1971945, 2339631, 2467665, 2339631, 1971945
Offset: 0
Links
- G. Kreweras, Sur les permutations comptées par les nombres de Genocchi de 1-ière et 2-ième espèce, Europ. J. Comb., vol. 18, pp. 49-58, 1997.
- G. Kreweras and D. Dumont, Sur les anagrammes alternés, Discrete Mathematics, Volume 211, Issues 1-3, 28 January 2000, Pages 103-110. Zbl 0944.05003.
Programs
-
Mathematica
a[ 1, 1 ]=1; a[ n_, k_ ] := 0 /; (k>n || k<=0); a[ n_, 1 ]=Sum[ a[ n-1, i ], {i, 1, n-1} ] a[ n_, k_ ] := a[ n, k ]=2a[ n, k-1 ]-a[ n, k-2 ]-a[ n-1, k-1 ]-a[ n-1, k-2 ]; Flatten[ Table[ a[ n, i ], {n, 1, 10}, {i, 1, n} ] ]
Extensions
More terms from Erich Friedman.