A108926 Initial members of abundant quintuplets, i.e., values of k such that (k, k+2, k+4, k+6, k+8) are all abundant numbers.

2988, 4728, 9724, 18844, 22984, 30544, 35148, 39948, 45048, 50464, 55788, 56808, 58056, 58780, 69184, 78048, 81948, 85744, 101148, 106144, 108256, 109248, 117124, 134088, 139744, 139804, 152568, 171288, 174348, 175908, 182644, 189768, 197028

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..5000 from Shyam Sunder Gupta)

Mathematica

SequencePosition[Table[If[DivisorSigma[1, n]>2n, 1, 0], {n, 200000}], {1, _, 1, _, 1, _, 1, _, 1}][[All, 1]] (* Harvey P. Dale, Mar 06 2022 *)

Prog

(PARI) is(n)=sigma(n, -1)>2 && sigma(n+2, -1)>2 && sigma(n+4, -1)>2 && sigma(n+6, -1)>2 && sigma(n+8, -1)>2 \\ Charles R Greathouse IV, Feb 21 2017

Crossrefs

Cf. A005101, A096399, A231086, A231089, A231090, A231092, A231093.

Sequence in context: A231628 A231623 A349063 * A159731 A221725 A205241

Adjacent sequences: A108923 A108924 A108925 * A108927 A108928 A108929

Keyword

nonn

Author

Jason Earls, Jul 19 2005

Status

approved