A193433 Sum of the divisors of n^2+1.

1, 3, 6, 18, 18, 42, 38, 93, 84, 126, 102, 186, 180, 324, 198, 342, 258, 540, 434, 546, 402, 756, 588, 972, 578, 942, 678, 1332, 948, 1266, 972, 1596, 1302, 1980, 1260, 1842, 1298, 2484, 1842, 2286, 1602, 2613, 2124, 3534, 2100, 3042, 2220, 4536, 2772, 3606

Offset

0,2

Links

Amiram Eldar, Table of n, a(n) for n = 0..10000

Formula

a(n) = A000203(A002522(n)). - Michel Marcus, Mar 16 2018

Example

a(7) = 93 because 7^2+1 = 50 and the sum of the 6 divisors { 1, 2, 5, 10, 25, 50} is 93.

Maple

with(numtheory):for n from 0 to 110 do:x:=divisors(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

Table[Total[Divisors[n^2 + 1]], {n, 0, 100}] (* T. D. Noe, Jul 28 2011 *)
DivisorSigma[1, Range[0, 50]^2+1] (* Harvey P. Dale, Aug 03 2020 *)

Prog

(PARI) a(n) = sigma(n^2+1); \\ Michel Marcus, Mar 17 2018

Crossrefs

Cf. A000203, A002522, A193432.

Sequence in context: A248324 A341119 A078318 * A074370 A174101 A088339

Adjacent sequences: A193430 A193431 A193432 * A193434 A193435 A193436

Keyword

nonn

Author

Michel Lagneau, Jul 28 2011

Status

approved