A322197 Antidiagonal sums of square table A322190.

1, 2, 3, 6, 15, 46, 168, 710, 3405, 18270, 108438, 705334, 4989075, 38126414, 313034088, 2748039078, 25685633625, 254672239678, 2669718010218, 29502715813142, 342784073066655, 4177349457737262, 53279132429530428, 709785147883342726, 9858698782067445765, 142530638751865262366, 2141519206261256136318, 33391802751245681847030, 539616796036523449056555, 9026558167976152019922190

Offset: 0

Author

Paul D. Hanna, Dec 20 2018

Keywords

• nonn

Comments

Table A322190 gives the coefficients of x^n*y^k/(n!*k!) in (cosh(x)*cosh(y) + sinh(x) + sinh(y)) / (1 - sinh(x)*sinh(y)).

Links

• Paul D. Hanna, Table of n, a(n) for n = 0..150

Crossrefs

Cf. A244920.

Programs

Mathematica

nmax = 30;
t[n_, k_] := SeriesCoefficient[(Cosh[x] Cosh[y] + Sinh[x] + Sinh[y])/(1 - Sinh[x] Sinh[y]), {x, 0, n}, {y, 0, k}] n! k!;
a[n_] := Sum[t[n - k, k], {k, 0, n}];
Table[a[n], {n, 0, nmax}] (* Jean-François Alcover, Dec 29 2018 *)

Formula

a(n) ~ Pi * n^(n+1) / (2^(n - 3/4) * exp(n) * (log(1+sqrt(2)))^(n + 3/2)). - Vaclav Kotesovec, Dec 30 2018