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A097259
Numbers whose set of base 13 digits is {0,C}, where C base 13 = 12 base 10.
2
0, 12, 156, 168, 2028, 2040, 2184, 2196, 26364, 26376, 26520, 26532, 28392, 28404, 28548, 28560, 342732, 342744, 342888, 342900, 344760, 344772, 344916, 344928, 369096, 369108, 369252, 369264, 371124, 371136, 371280, 371292, 4455516
OFFSET
0,2
COMMENTS
n such that there exists a permutation p_1, ..., p_n of 1, ..., n such that i + p_i is a power of 13 for every i.
LINKS
FORMULA
a(n) = 12*A033049(n).
a(2n) = 13*a(n), a(2n+1) = a(2n)+12.
MATHEMATICA
f[n_] := FromDigits[ IntegerDigits[n, 2] /. {1 -> 12}, 13]; Array[f, 33, 0] (* or much slower *)
fQ[n_] := Union@ Join[{0, 12}, IntegerDigits[n, 13]] == {0, 12}; Select[ Range[0, 4455516 ], fQ] (* Robert G. Wilson v, May 12 2012 *)
FromDigits[#, 13]&/@Tuples[{0, 12}, 5] (* Vincenzo Librandi, Jun 04 2012 *)
PROG
(Magma) [n: n in [0..4500000] | Set(IntegerToSequence(n, 13)) subset {0, 12}]; // Vincenzo Librandi, Jun 04 2012
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Ray Chandler, Aug 03 2004
STATUS
approved