A234861 Sum of the distinct prime divisors of n^3 - 1.

0, 7, 15, 10, 33, 48, 24, 80, 22, 40, 33, 168, 66, 224, 250, 28, 309, 24, 132, 440, 470, 23, 99, 624, 43, 61, 772, 274, 89, 55, 341, 189, 1125, 411, 129, 86, 79, 1520, 251, 563, 1730, 193, 643, 333, 141, 118, 123, 241, 67, 2558, 393, 939, 431, 3024, 97, 150

Offset: 1

Author

Vincenzo Librandi, Jan 01 2014

Keywords

• nonn

Examples

			a(3) = 15 because 3^3-1 = 26 and the sum of the 2 distinct prime divisors {2, 13} is 15.
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A062835.

Programs

Mathematica

Table[Total[Transpose[FactorInteger[n^3 - 1]][[1]]], {n, 50}]