A080288 Successively larger gaps between Ulam numbers.

1, 2, 3, 8, 9, 10, 12, 20, 27, 30, 34, 39, 41, 42, 69, 78, 100, 122, 137, 262, 315, 587, 609, 631, 758, 890, 1083, 1092, 1114, 1364, 1373

Offset

1,2

Comments

The lower term of the gaps is in A080287.

Links

Table of n, a(n) for n=1..31.

Philip Gibbs, Judson McCranie, The Ulam Numbers up to One Trillion, (2017).

Example

87 and 97 are successive Ulam numbers and this is the first gap of 10 or larger, so 10 is in the sequence.

Crossrefs

Cf. A002858, A080287, A214603, A274522.

Sequence in context: A037318 A253317 A277971 * A278560 A217682 A169868

Adjacent sequences: A080285 A080286 A080287 * A080289 A080290 A080291

Keyword

nonn,more,hard

Author

Jud McCranie, Feb 12 2003

Extensions

23rd term found by Don Knuth - Jud McCranie, Aug 22 2008

a(24) on Feb 29 2012; a(25) on Jul 20 2012; and a(26) on Jul 24 2012 found by Jud McCranie;

a(27) found by Philip Gibbs, Sep 02 2015

a(28) found by Philip Gibbs and Jud McCranie, Sep 09 2015

a(29) found by Philip Gibbs, Oct 2017

a(30) found by Philip Gibbs, Oct 16 2017

a(31) found by Philip Gibbs, Oct 20 2017

Missing a(23) inserted by Jud McCranie, Oct 24 2017

Status

approved