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.
FORMULA
a(n) = SUM[i=1..n] A018190(i).
EXAMPLE
a(6) = 1 + 1 + 3 + 7 + 22 + 81 = 115.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Apr 22 2010
STATUS
approved