A324349 a(n) = A324122(A005940(1+n)), where A005940 is the Doudna sequence and A324122(n) = sigma(n) - gcd(n*d(n), sigma(n)).

0, 2, 2, 6, 4, 0, 12, 14, 6, 16, 12, 24, 30, 36, 36, 30, 10, 16, 28, 36, 44, 48, 72, 48, 54, 90, 122, 90, 152, 96, 120, 60, 12, 32, 36, 0, 68, 48, 102, 80, 92, 128, 168, 144, 246, 216, 120, 120, 132, 168, 222, 216, 336, 360, 402, 192, 396, 464, 600, 272, 780, 360, 362, 126, 16, 40, 52, 72, 80, 96, 150, 112, 84, 208, 264, 112, 366, 288, 312, 184, 164, 272, 360, 0, 568

Offset

0,2

Comments

Zeros occur in the same positions as in A324057, and can be obtained by sorting into ascending order the terms obtained with A156552(A001599(n)), n >= 1.

Links

Antti Karttunen, Table of n, a(n) for n = 0..16384

Antti Karttunen, Data supplement: n, a(n) computed for n = 0..65537

Formula

a(n) = A324122(A005940(1+n)).

a(n) = A324054(n) - A324058(n).

For n > 0, a(n) = A324189(A054429(n)).

Prog

(PARI)
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t }; \\ From A005940
A324122(n) = (sigma(n) - gcd(sigma(n), n*numdiv(n)));
A324349(n)  = A324122(A005940(1+n));

Crossrefs

Cf. A005940, A054429, A324054, A324057, A324058, A324189

Cf. also A001599.

Sequence in context: A334870 A324122 A374408 * A092384 A061915 A366898

Adjacent sequences: A324346 A324347 A324348 * A324350 A324351 A324352

Keyword

nonn

Author

Antti Karttunen, Feb 24 2019

Status

approved