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%I #34 Aug 13 2020 14:02:28
%S 1,2,3,4,5,6,7,8,9,81,89,136,264,333,337,425,441,445,1250,1251,1252,
%T 1253,1254,1255,1256,1257,1258,1259,1306,1346,1386,1521,1525,1634,
%U 1636,1674,1693,1745,2025,2116,2225,2401,2403,2407,2465,2536,2576,2601,2624
%N Numbers which can be written with their digits in order and using only a plus and a squaring operator.
%C Erich Friedman calls them S-numbers. It was proved that such numbers are infinitely many but their density is 0.
%H Erich Friedman, <a href="https://erich-friedman.github.io/mathmagic/0803.html">Problem of the Month, August 2003</a>
%e 81 = (8 + 1)^2.
%e 89 = 8 + 9^2.
%e 136 = (1 + 3^2)^2 + 6^2.
%e 264 = 2 + 6 + (4^2)^2.
%K nonn,base
%O 1,2
%A _Kausthub Gudipati_, Aug 31 2011
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