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A339218
Number of partitions of n into prime parts where every part appears at least 2 times.
8
1, 0, 0, 0, 1, 0, 2, 0, 1, 1, 3, 0, 3, 1, 4, 3, 5, 1, 6, 4, 8, 6, 9, 5, 12, 9, 14, 11, 17, 13, 22, 17, 24, 21, 31, 26, 37, 31, 42, 39, 52, 46, 61, 56, 71, 67, 84, 79, 100, 95, 114, 111, 135, 131, 158, 154, 180, 180, 212, 209, 244, 244, 280, 283, 324, 325, 372, 378, 426, 434, 487
OFFSET
0,7
FORMULA
G.f.: Product_{k>=1} (1 + x^(2*prime(k)) / (1 - x^prime(k))).
EXAMPLE
a(10) = 3 because we have [5, 5], [3, 3, 2, 2] and [2, 2, 2, 2, 2].
MATHEMATICA
nmax = 70; CoefficientList[Series[Product[1 + x^(2 Prime[k])/(1 - x^Prime[k]), {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 27 2020
STATUS
approved