A294574 Numbers having exactly one representation as sum of squares of primes.

4, 8, 9, 12, 13, 16, 17, 18, 20, 21, 22, 24, 26, 27, 28, 30, 31, 32, 35, 39

Offset: 1

Author

Ilya Gutkovskiy, Nov 02 2017

Keywords

• nonn
• fini
• full

Links

• Index entries for sequences related to sums of squares

Crossrefs

Cf. A001248, A078135, A078136, A090677, A134755.

Programs

Mathematica

Flatten[Position[Rest[CoefficientList[Series[Product[1/(1 - x^(Prime[k]^2)), {k, 1, 5}], {x, 0, 40}], x]], 1]]

Formula

A090677(a(n)) = 1.