A078382 Sum of divisors of numbers which can be written as sum of a positive square and a positive cube.

3, 6, 13, 18, 28, 18, 60, 42, 56, 32, 48, 91, 38, 44, 84, 93, 98, 80, 104, 84, 126, 195, 74, 140, 186, 126, 90, 112, 217, 102, 280, 114, 186, 312, 128, 255, 176, 204, 192, 180, 266, 372, 300, 192, 294, 324, 260, 360, 240, 228, 320, 399, 198, 504, 312, 434, 256

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A000203(A055394(n)).

Mathematica

DivisorSigma[1, Select[Range[200], Length[Reduce[a^2 + b^3 == # && a > 0 && b > 0, {a, b}, Integers]] > 0 &]] (* Amiram Eldar, Mar 27 2025 *)

Crossrefs

Cf. A000203, A055394, A078381, A078383, A078384.

Sequence in context: A293794 A379789 A115283 * A075651 A091277 A277690

Adjacent sequences: A078379 A078380 A078381 * A078383 A078384 A078385

Keyword

nonn

Author

Reinhard Zumkeller, Nov 25 2002

Status

approved