A100382 Record values of A062700.

3, 7, 13, 31, 127, 307, 1093, 1723, 2801, 3541, 8191, 10303, 19531, 28057, 30941, 131071, 147073, 524287, 797161, 830833, 1191373, 1204507, 1353733, 1395943, 1424443, 1482307, 1886503, 2037757, 2212657, 2432041, 2507473, 2922391

Offset

1,1

Comments

Take sequence A062700: 3, 7, 13, 31, 31, 127, 307, 1093, 1723, 2801, 3541, 8191, 5113, 8011, 10303, .... Then eliminate terms so that each term of the sequence is larger than the preceding one: 3, 7, 13, 31, 127, 307, 1093, 1723, 2801, 3541, 8191, 10303, ....

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Prog

(Magma) S:=[]; a:=0; for n in [1..3000000] do c:=SumOfDivisors(n); if IsPrime(c) and a lt c then Append(~S, c); a:=c; end if; end for; S; // Klaus Brockhaus, Oct 21 2009

Crossrefs

Cf. A062700 (terms of A000203 that are prime), A000203 (sigma(n), sum of divisors of n), A034885 (record values of sigma(n)).

Sequence in context: A253850 A087578 A023195 * A292448 A222227 A152981

Adjacent sequences: A100379 A100380 A100381 * A100383 A100384 A100385

Keyword

nonn

Author

Jorge Coveiro, Dec 30 2004

Extensions

More terms from Ryan Propper, Jul 13 2005

Edited, corrected and extended by Klaus Brockhaus, Oct 21 2009

Status

approved