A336645 a(n) = n - A326129(n).

0, 1, 1, 3, 1, 6, 1, 7, 8, 8, 1, 11, 1, 10, 9, 15, 1, 17, 1, 19, 11, 14, 1, 18, 24, 16, 25, 7, 1, 18, 1, 31, 15, 20, 13, 35, 1, 22, 17, 30, 1, 30, 1, 43, 41, 26, 1, 47, 48, 49, 21, 49, 1, 42, 17, 54, 23, 32, 1, 57, 1, 34, 61, 63, 19, 54, 1, 67, 27, 66, 1, 71, 1, 40, 73, 73, 19, 66, 1, 79, 80, 44, 1, 77, 23, 46, 33, 86, 1, 88, 21

Offset: 1

Author

Antti Karttunen, Jul 29 2020

Keywords

• nonn

Comments

It seems that A000396 gives all such n for which a(n) = A007913(n).

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384
• Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Crossrefs

Cf. A000203, A000396, A007913, A326126, A326127, A326128, A326129.

Programs

PARI

A326127(n) = (sigma(n)-core(n)-n);
A326128(n) = (n-core(n));
A336645(n) = (n-gcd(A326127(n), A326128(n)));

Formula

a(n) = n - A326129(n) = n - gcd(A326127(n), A326128(n)).