A083090 Main diagonal of table A083087.

1, 5, 25, 90, 247, 766, 2258, 5860, 16526, 45639, 124043, 313327, 837221, 2216256, 5545541, 14524810, 37810204, 97907017, 242993558, 625252309, 1602714963, 3962518559, 10109705767, 25718726896, 63402237401, 160711911464

Offset: 0

Author

Paul D. Hanna, Apr 22 2003

Keywords

• nonn

Crossrefs

Cf. A083087, A083044, A083047, A083050.

Formula

a(n) = T(n, n), where T(n, 0) = floor(n*x/(x-1)) + 1, T(n, k+1) = ceiling(x*T(n, k)), for n >= 0, k >= 0, where x = 1+sqrt(2).