A154381 Row sums of Bell related number triangle A154380.

1, 2, 6, 20, 72, 276, 1120, 4804, 21796, 104784, 534788, 2901580, 16742440, 102654356, 667519492, 4590552960, 33278208004, 253436345340, 2020974497112, 16823488830836, 145798111066964, 1312272490908464

Offset: 0

Author

Paul Barry, Jan 08 2009

Keywords

• easy
• nonn

Comments

a(n) = 2*A129247(n), n>0. Hankel transform is 2^n*A000178(n).

Crossrefs

Cf. A000110, A000178, A129247, A154380.

Formula

G.f.: 1/(1-2x/(1-x/(1-x/(1-2x/(1-x/(1-3x/(1-x/(1-4x/(1-... (continued fraction).