A257177 Number of partitions of n into 2 or 3 primes.

0, 0, 0, 1, 1, 2, 2, 2, 3, 3, 2, 3, 3, 3, 4, 4, 4, 4, 4, 4, 6, 5, 5, 6, 6, 6, 7, 5, 7, 5, 7, 5, 10, 6, 8, 8, 9, 6, 11, 5, 11, 7, 11, 7, 13, 7, 13, 9, 13, 9, 15, 7, 16, 8, 15, 8, 17, 7, 16, 10, 17, 9, 20, 8, 21, 11, 20, 8, 21, 7, 22, 11, 22, 11, 23, 10, 28, 12, 24, 11

Offset

1,6

Links

Table of n, a(n) for n=1..80.

Mathematica

 f[n_] := Length@ IntegerPartitions[n, {2, 3}, Prime@ Range@ PrimePi@ n]; Array[f, 80]

Crossrefs

Cf. A002375, A068307, A083338, A000607.

Sequence in context: A272851 A242258 A232615 * A243423 A094528 A077774

Adjacent sequences: A257174 A257175 A257176 * A257178 A257179 A257180

Keyword

nonn,easy

Author

Robert G. Wilson v, Apr 17 2015

Status

approved