A026582 a(n) = Sum{T(i,j)}, 0<=j<=i, 0<=i<=n, T given by A026568.

1, 3, 8, 20, 50, 125, 314, 792, 2003, 5079, 12897, 32798, 83478, 212657, 542040, 1382376, 3526916, 9001805, 22982298, 58691692, 149919707, 383028163, 978768731, 2501494110, 6394118165, 16346237219, 41793150985, 106865638630

Offset: 0

Author

Clark Kimberling

Keywords

• nonn

Formula

Conjecture: n*a(n) +2*(-2*n+1)*a(n-1) +2*(-n+3)*a(n-2) +20*(n-2)*a(n-3) +(-7*n+6)*a(n-4) +2*(-12*n+41)*a(n-5) +8*(2*n-7)*a(n-6)=0. - R. J. Mathar, Jun 23 2013