A346388 - OEIS

A346388

a(n) is the number of proper divisors of A053742(n) ending with 5.

1, 3, 2, 3, 5, 3, 3, 5, 3, 3, 7, 3, 3, 7, 3, 3, 7, 5, 3, 7, 3, 3, 8, 3, 5, 7, 3, 5, 7, 3, 3, 11, 5, 3, 7, 3, 3, 7, 7, 3, 9, 3, 5, 7, 3, 7, 7, 5, 3, 11, 3, 3, 11, 3, 3, 7, 3, 5, 11, 7, 5, 7, 4, 3, 7, 3, 7, 11, 3, 3, 7, 7, 5, 11, 3, 3, 11, 5, 3, 7, 7, 3, 11, 3, 5

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

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..84.

FORMULA

a(n) = A346392(A053742(n)).

EXAMPLE

a(10) = 7 since there are 7 proper divisors of A053742(10) = 525 ending with 5: 5, 15, 25, 35, 75, 105 and 175.

MATHEMATICA

a[n_]:=Length[Drop[Select[Divisors[25+50n], (Mod[#, 10]==5&)], -1]]; Array[a, 90, 0]

CROSSREFS