A340197 a(1) = 1; for n > 1, a(n) = Sum_{d|n, d<n} (A318833(n/d)-1) * A340197(d).

1, 0, 0, 2, 0, 7, 0, 6, 6, 13, 0, 13, 0, 19, 22, 18, 0, 19, 0, 23, 32, 31, 0, 53, 20, 37, 24, 33, 0, 21, 0, 54, 52, 49, 58, 110, 0, 55, 62, 95, 0, 29, 0, 53, 52, 67, 0, 185, 42, 53, 82, 63, 0, 139, 94, 137, 92, 85, 0, 321, 0, 91, 74, 162, 112, 45, 0, 83, 112, 45, 0, 403, 0, 109, 82, 93, 136, 53, 0, 331, 114, 121

Offset

1,4

Comments

See comments and question in A340140.

Links

Antti Karttunen, Table of n, a(n) for n = 1..16384

Formula

a(1) = 1; for n > 1, a(n) = Sum_{d|n, d<n} (A318833(n/d)-1) * A340197(d).

Prog

(PARI)
A023900(n) = factorback(apply(p -> 1-p, factor(n)[, 1]));
A318833(n) = (n+A023900(n));
A340197(n) = if(1==n, 1, sumdiv(n, d, if(d<n, (A318833(n/d)-1)*A340197(d), 0)));

Crossrefs

Cf. A023900, A318833, A340140, A340367.

Sequence in context: A369745 A197391 A340367 * A340140 A334341 A285174

Adjacent sequences: A340194 A340195 A340196 * A340198 A340199 A340200

Keyword

nonn

Author

Antti Karttunen, Jan 05 2021

Status

approved