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 A035502 #20 Jul 08 2025 21:33:29 %S A035502 31,129,192,262,301,319,367,391,565,622,637,655,912,931,1029,1092, %T A035502 1114,1121,1151,1184,1211,1221,1257,1274,1299,1332,1447,1474,1511, %U A035502 1527,1574,1581,1724,1744,1754,1771,1784,1814,1851,1874,1880,1881,1902,1929,2062 %N A035502 Lower of pair of consecutive happy numbers. %D A035502 R. K. Guy, Unsolved Problems Number Theory, Sect. E34. %H A035502 Amiram Eldar, <a href="/A035502/b035502.txt">Table of n, a(n) for n = 1..10000</a> %H A035502 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HappyNumber.html">Happy Number</a> %t A035502 f[n_] := Total[IntegerDigits[n]^2]; t = Select[Range[5000], NestWhile[f, #, UnsameQ, All] == 1 &]; t[[Select[Range[Length[t] - 1], t[[#]] == t[[# + 1]] - 1 &]]] (* _T. D. Noe_, Aug 23 2011 *) %Y A035502 Cf. A007770, A035503. %K A035502 nonn,easy,base %O A035502 1,1 %A A035502 _N. J. A. Sloane_ %E A035502 More terms from _Sascha Kurz_, Mar 24 2002