This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A080287 #69 Jun 27 2025 23:30:01 %S A080287 1,4,8,18,38,87,114,155,282,751,949,1257,1553,1858,2178,4800,5384, %T A080287 18796,37562,64420,252719,933709,289738117,332250401,667752899, %U A080287 699497052,966290117,224582902442,319654121875,418843012121,802386465583 %N A080287 Successively larger gaps in Ulam numbers start at this Ulam number. %C A080287 The gaps are in A080288. %D A080287 D. E. Knuth, The Art of Computer Programming, vol 4A, section 7.1.3, exercise 141. %H A080287 Philip Gibbs, Judson McCranie, <a href="https://www.researchgate.net/profile/Philip_Gibbs/publication/320980165_The_Ulam_Numbers_up_to_One_Trillion/links/5a058786aca2726b4c78588d/The-Ulam-Numbers-up-to-One-Trillion.pdf">The Ulam Numbers up to One Trillion</a>, (2017). %e A080287 87 and 97 are successive Ulam numbers and this is the first gap of 10 or larger, so 87 is in the sequence. %Y A080287 Cf. A002858, A080288, A214603, A274522. %K A080287 nonn,more,hard %O A080287 1,2 %A A080287 _Jud McCranie_, Feb 12 2003 %E A080287 Added a(23) found by _Don Knuth_ - _Jud McCranie_, Aug 22 2008 %E A080287 a(24) on Feb 29 2012; a(25) on Jul 20 2012; and a(26) on Jul 24 2012 by _Jud McCranie_ %E A080287 a(27) found by Philip Gibbs, Sep 02 2015 %E A080287 a(28) found by Philip Gibbs and _Jud McCranie_, Sep 09 2015 %E A080287 a(29)-a(31) found by Philip Gibbs, Oct 27 2017 %E A080287 Missing term a(23) added by Jud McCranie, Oct 27 2017