A176638 Partial sums of A018190.

1, 2, 5, 12, 34, 115, 446, 1881, 8386, 38472, 179701, 849285, 4047541, 19415118, 93623028, 453486806, 2205081449, 10758731196, 52651373968, 258365785954, 1270930958357, 6265738653554, 30952863554094, 153191072337297

Offset

1,2

Comments

Partial sums of number of planar simply-connected polyhexes (or benzenoid hydrocarbons) with n hexagons. The only known primes in the partial sum are 2 and 5.

Links

Table of n, a(n) for n=1..24.

Formula

a(n) = SUM[i=1..n] A018190(i).

Example

a(6) = 1 + 1 + 3 + 7 + 22 + 81 = 115.

Crossrefs

Cf. A000228, A002216, A018190, A038142-A038147.

Sequence in context: A151408 A121956 A348102 * A131467 A000103 A101292

Adjacent sequences: A176635 A176636 A176637 * A176639 A176640 A176641

Keyword

nonn

Author

Jonathan Vos Post, Apr 22 2010

Status

approved