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

0, 1, 4, 9, 64, 81, 513, 1216, 6400, 14337, 234496, 483328, 2502657, 17432577, 18399232, 412549120, 842530816, 4317249537, 11162091520, 50755272705, 692253097984, 2178269839360, 6737830608897, 46758772080640, 60234433298433, 474731593596928, 809186870951937

Offset

1,3

Links

Eric M. Schmidt, Table of n, a(n) for n = 1..1000

Example

a(3) = 4 = (4)_12 since 4^2 = 16 = (14)_12 ends with 4 in base 12.
a(4) = 9 = (9)_12 since 9^2 = 81 = (69)_12 ends with 9 in base 12.
a(5) = 64 = (54)_12 since 64^2 = 4096 = (2454)_12 ends with 54 in base 12.

Mathematica

a201918[n_Integer] := Module[{i = 0}, Flatten[Last[Reap[
     Do[If[
       IntegerDigits[i^2, 12][[-Length[IntegerDigits[i, 12]] ;; -1]] ==
         IntegerDigits[i, 12], Sow[i]], {i, n}]]]]]; a201918[12^6] (* Michael De Vlieger, Aug 13 2014 *)

Prog

(Sage) # See A003226. - Eric M. Schmidt, Feb 09 2014

Crossrefs

Cf. A003226, A201821, A201919, A201921, A201948, A237583.

Sequence in context: A069495 A029788 A062826 * A263675 A140483 A124683

Adjacent sequences: A201915 A201916 A201917 * A201919 A201920 A201921

Keyword

nonn,base

Author

Martin Renner, Dec 06 2011

Extensions

More terms from Eric M. Schmidt, Feb 09 2014

Status

approved