A193462 Sum of the distinct prime divisors of n^2+1.

0, 2, 5, 7, 17, 15, 37, 7, 18, 43, 101, 63, 34, 24, 197, 115, 257, 36, 18, 183, 401, 32, 102, 60, 577, 315, 677, 80, 162, 423, 70, 52, 46, 116, 102, 615, 1297, 144, 22, 763, 1601, 31, 358, 44, 162, 1015, 102, 37, 466, 1203, 102, 1303, 546, 288, 2917, 108, 3137

Offset

0,2

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Example

a(7) = 7 because 7^2+1 = 2*5^2 and the sum of the 2 distinct prime divisors {2, 5} is 7.

Maple

with(numtheory):for n from 0 to 110 do:x:=factorset(n^2+1):n1:=nops(x):s:=0:for m from 1 to n1 do: s:=s+x[m]:od: printf(`%d, `, s):od:

Mathematica

Join[{0}, Table[Total[Transpose[FactorInteger[n^2+1]][[1]]], {n, 60}]] (* Harvey P. Dale, Oct 18 2013 *)

Crossrefs

Cf. A193432, A193433.

Sequence in context: A145674 A067161 A281794 * A306636 A101150 A276322

Adjacent sequences: A193459 A193460 A193461 * A193463 A193464 A193465

Keyword

nonn

Author

Michel Lagneau, Jul 28 2011

Status

approved