OFFSET
0,42
LINKS
Eric Weisstein's World of Mathematics, Centered Square Number
FORMULA
G.f.: Product_{k>=1} 1/(1 - x^A027862(k)).
EXAMPLE
a(41) = 2 because we have [41] and [13, 13, 5, 5, 5].
MATHEMATICA
nmax = 100; CoefficientList[Series[Product[1/(1 - x^k), {k, Select[Range[nmax]^2 + (Range[nmax] + 1)^2, PrimeQ]}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, May 16 2017
STATUS
approved