OFFSET
0,14
COMMENTS
Number of compositions (ordered partitions) of n into squares of primes (A001248).
From Ilya Gutkovskiy, Feb 12 2017: (Start)
Conjecture(1): every number > 23 is the sum of at most 8 squares of primes.
Conjecture(2): every number > 131 can be represented as a sum of 13 squares of primes. (End)
LINKS
FORMULA
G.f.: 1/(1 - Sum_{k>=1} x^(prime(k)^2)).
EXAMPLE
a(17) = 3 because we have [4, 4, 9], [4, 9, 4] and [9, 4, 4].
MATHEMATICA
nmax = 85; CoefficientList[Series[1/(1 - Sum[x^Prime[k]^2, {k, 1, nmax}]), {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Dec 24 2016
STATUS
approved