A112640 Odd abundant numbers divisible neither by 5 nor 7.

28683369, 36165987, 38660193, 86050107, 108497961, 115980579, 131339637, 138428433, 140397543, 153393669, 160876287, 258150321, 277272567, 296394813, 315517059, 325493883, 347941737, 353761551, 372883797, 373715199, 392006043

Offset

1,1

Comments

Subsequence of A064001 which itself is a subsequence of A005231. All 500 terms in b-file are divisible by 99. Cf. also A047802. - Zak Seidov, Mar 30 2011

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..500 from Zak Seidov)

C. Rivera, Puzzle 329. Odd abundant numbers not divided by 2 or 3.

Mathematica

Do[If[Mod[n, 5]>0&&Mod[n, 7]>0&&DivisorSigma[1, n]>2n, Print[n]], {n, 28683369, 6*10^9, 2}] (* Zak Seidov, Mar 30 2011 *)

Prog

(PARI) is(n)=gcd(n, 70)==1 && sigma(n, -1)>2 \\ Charles R Greathouse IV, Feb 21 2017

Crossrefs

Cf. A064001, A110585.

Sequence in context: A213914 A345629 A346284 * A200217 A364221 A306845

Adjacent sequences: A112637 A112638 A112639 * A112641 A112642 A112643

Keyword

nonn

Author

Labos Elemer, Sep 15 2005

Extensions

Extended by Ray Chandler, Sep 19 2005

Status

approved