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%I #39 Sep 08 2022 08:44:50
%S 1,4,9,10,13,18,22,27,31,36,40,45,54,63,72,79,81,88,90,97,100,103,108,
%T 112,117,121,126,130,135,144,153,162,169,171,178,180,187,196,202,207,
%U 211,216,220,225,234,243,252,259,261,268,270,277,286,295,301,306,310
%N Sum of digits of n is a square.
%C Difference between two consecutive terms is never equal to 8. - _Carmine Suriano_, Mar 31 2014
%C In this sequence, there is no number of the form 3*k-1. In other words, if a(n) is not divisible by 9, it must be of the form 3*k+1. - _Altug Alkan_, Apr 08 2016
%H Carmine Suriano, <a href="/A028839/b028839.txt">Table of n, a(n) for n = 1..1242</a>
%e 234511 belongs to the sequence as its sum of digits is 16, a square.
%t Select[ Range[ 500 ], IntegerQ[ Sqrt[ Apply[ Plus, IntegerDigits[ # ] ] ] ]& ]
%o (Magma) [n: n in [1..400] | IsSquare(&+Intseq(n))]; // _Bruno Berselli_, May 26 2011
%o (PARI) isok(n) = issquare(sumdigits(n)); \\ _Michel Marcus_, Oct 30 2014
%Y Cf. A007953, A028837, A050626.
%Y Cf. A053057 (squares whose digit sum is also a square).
%K nonn,base,easy
%O 1,2
%A _N. J. A. Sloane_.
%E More terms from _Erich Friedman_
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