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

Author

Jud McCranie, Feb 12 2003

Keywords

• nonn
• more
• hard

Comments

The lower term of the gaps is in A080287.

Examples

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

Links

• Philip Gibbs and Judson McCranie, The Ulam Numbers up to One Trillion, (2017).
• Shyam Sunder Gupta, Ulam Numbers. In: Exploring the Beauty of Fascinating Numbers. Springer Praxis Books(). Springer, Singapore, (2025).

Crossrefs

Cf. A002858, A080287, A214603, A274522.

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

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