A328387 Numbers k such that A276086(k) is a multiple of k.

1, 3, 15, 25, 75, 105, 147, 175, 343, 385, 525, 539, 625, 735, 825, 1029, 1155, 1225, 1331, 1375, 1617, 1815, 2695, 3003, 3025, 3675, 3773, 3993, 4375, 5005, 5145, 5577, 5775, 6655, 6825, 8085, 8125, 8281, 8575, 9075, 9555, 9625, 10725, 11011, 11319, 12675, 12705, 13013, 13377, 15015, 15379, 15925, 17303, 17745, 17787, 17875

Offset: 1

Author

Antti Karttunen, Oct 15 2019

Keywords

• nonn

Comments

All terms are odd. Of the first 3003 terms, 1709 are multiples of five.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..3003

Crossrefs

Cf. A276086, A324198.

Indices of 0's in A328386. Indices of 1's in A351250.

Subsequence of A048103 and of A358226.

Cf. also A370114, A358231.

Programs

PARI

A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
isA328387(n) = (0==(A276086(n)%n));