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%I M3377 N1361 #32 Apr 22 2023 14:04:14
%S 1,4,10,17,27,40,54,71,100,121,144,170,207,237,270,314,351,400,441,
%T 484,540,587,647,710,764,831,1000,1061,1134,1210,1277,1357,1440,1524,
%U 1611,1700,1781,1874,2070,2167,2267,2370,2474,2581,2700,2811,3024,3140,3257
%N Squares written in base 9.
%D GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See pages 108 and 300.
%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%D V. Thébault, Les Récréations Mathématiques. Gauthier-Villars, Paris, 1952, p. 98.
%H Robert Israel, <a href="/A002442/b002442.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = A007095(A000290(n)). - _Jason Kimberley_, Dec 13 2012
%p f:= proc(n) local L,i;
%p L:= convert(n^2,base,9);
%p add(L[i]*10^(i-1),i=1..nops(L))
%p end proc:
%p map(f, [$1..100]); # _Robert Israel_, Aug 12 2018
%t Table[FromDigits[IntegerDigits[n^2, 9]], {n, 1, 100}] (* _Stefan Steinerberger_, Apr 11 2006 *)
%o (Magma) [Seqint(Intseq(n^2, 9)): n in [1..60]]; // _Vincenzo Librandi_, Oct 16 2015
%o (PARI) a(n) = fromdigits(digits(n^2, 9)); \\ _Michel Marcus_, Aug 13 2018
%Y Cf. A000290, A007095.
%K nonn,base,easy
%O 1,2
%A _N. J. A. Sloane_
%E More terms from _Stefan Steinerberger_, Apr 11 2006
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