A006898 a(n) = Sum_{k=0..n} C(n,k)*2^(k*(k+1)/2). (Formerly M2958)

1, 3, 13, 95, 1337, 38619, 2310533, 283841911, 70927591153, 35812691480115, 36383765777442685, 74185239630793429775, 303119284294591169426729, 2479814853198140771706795531, 40599509058360322571947638063605

Offset

0,2

Comments

First differences of A006896.

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=0..14.

Formula

a(n) ~ 2^(n*(n+1)/2). - Vaclav Kotesovec, Nov 27 2017

Mathematica

Table[Sum[Binomial[n, k]2^((k(k+1))/2), {k, 0, n}], {n, 0, 20}] (* Harvey P. Dale, Apr 01 2023 *)

Prog

(PARI) a(n)=sum(k=0, n, binomial(n, k)*2^(k*(k+1)/2)) \\ Paul D. Hanna, Apr 10 2009

Crossrefs

Cf. A006896, A006897, A135748.

Sequence in context: A305207 A369197 A183283 * A277492 A342305 A275528

Adjacent sequences: A006895 A006896 A006897 * A006899 A006900 A006901

Keyword

nonn

Author

Colin Mallows

Extensions

Formula and more terms from Vladeta Jovovic, Sep 20 2003

Edited by N. J. A. Sloane, Apr 12 2009 at the suggestion of Vladeta Jovovic

Status

approved