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A201918 Automorphic numbers: n^2 ends with n in base 12 (written in base 10).

%I A201918 #20 Mar 19 2020 14:51:57
%S A201918 0,1,4,9,64,81,513,1216,6400,14337,234496,483328,2502657,17432577,
%T A201918 18399232,412549120,842530816,4317249537,11162091520,50755272705,
%U A201918 692253097984,2178269839360,6737830608897,46758772080640,60234433298433,474731593596928,809186870951937
%N A201918 Automorphic numbers: n^2 ends with n in base 12 (written in base 10).
%H A201918 Eric M. Schmidt, <a href="/A201918/b201918.txt">Table of n, a(n) for n = 1..1000</a>
%e A201918 a(3) = 4 = (4)_12 since 4^2 = 16 = (14)_12 ends with 4 in base 12.
%e A201918 a(4) = 9 = (9)_12 since 9^2 = 81 = (69)_12 ends with 9 in base 12.
%e A201918 a(5) = 64 = (54)_12 since 64^2 = 4096 = (2454)_12 ends with 54 in base 12.
%t A201918 a201918[n_Integer] := Module[{i = 0}, Flatten[Last[Reap[
%t A201918      Do[If[
%t A201918        IntegerDigits[i^2, 12][[-Length[IntegerDigits[i, 12]] ;; -1]] ==
%t A201918          IntegerDigits[i, 12], Sow[i]], {i, n}]]]]]; a201918[12^6] (* _Michael De Vlieger_, Aug 13 2014 *)
%o A201918 (Sage) # See A003226. - _Eric M. Schmidt_, Feb 09 2014
%Y A201918 Cf. A003226, A201821, A201919, A201921, A201948, A237583.
%K A201918 nonn,base
%O A201918 1,3
%A A201918 _Martin Renner_, Dec 06 2011
%E A201918 More terms from _Eric M. Schmidt_, Feb 09 2014