A234646 - OEIS

A234646

Sum of the distinct prime divisors of n^3 + 1.

0, 2, 3, 9, 18, 12, 38, 45, 22, 80, 31, 42, 39, 166, 69, 213, 258, 25, 326, 14, 137, 434, 486, 18, 91, 616, 41, 65, 786, 281, 111, 28, 345, 177, 1135, 402, 147, 95, 90, 1490, 271, 559, 1766, 165, 639, 315, 175, 115, 105, 201, 82, 2566, 439, 924, 432, 2980, 114

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

EXAMPLE

a(3) = 9 because 3^3+1 = 28 and the sum of the 2 distinct prime divisors {2, 7} is 9.

MATHEMATICA

Join[{0}, Table[Total[Transpose[FactorInteger[n^3 + 1]][[1]]], {n, 60}]]

CROSSREFS

Cf. A193462.

Sequence in context: A302164 A295965 A034467 * A065965 A296052 A108827

Adjacent sequences: A234643 A234644 A234645 * A234647 A234648 A234649

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Jan 01 2014

STATUS

approved