

A193562


Number of divisors of n^4+1.


3



1, 2, 2, 4, 2, 4, 2, 4, 4, 8, 4, 4, 4, 4, 4, 8, 2, 4, 4, 8, 2, 4, 4, 4, 2, 8, 4, 8, 2, 4, 4, 8, 4, 8, 2, 4, 4, 8, 4, 4, 4, 8, 4, 16, 8, 8, 2, 8, 2, 8, 4, 8, 4, 8, 2, 8, 2, 4, 4, 16, 8, 4, 4, 8, 8, 4, 8, 8, 4, 8, 8, 4, 4, 4, 2, 8, 8, 16, 4, 16, 2, 4, 2, 16, 4
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OFFSET

0,2


COMMENTS

This is to n^4+1 as A193432 is to n^2+1.
a(n) = 2 when n^4+1 is prime, iff n is in A037896.


LINKS



FORMULA

a(n) = A000005(A002523(n)) = d(n^4+1) (also called tau(n^4+1) or sigma_0(n^4+1)), the number of divisors of n^4+1.


EXAMPLE

a(3) = 4 because 3^4+1 = 82, whose 4 factors are {1, 2, 41, 82}.


MATHEMATICA



PROG

(Magma) [NumberOfDivisors(n^4+1):n in [0..90]]; // Marius A. Burtea, Feb 09 2020


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



STATUS

approved



