A072961 Numbers using only the digits 2 and 5, that are both curved and straight.

2, 5, 22, 25, 52, 55, 222, 225, 252, 255, 522, 525, 552, 555, 2222, 2225, 2252, 2255, 2522, 2525, 2552, 2555, 5222, 5225, 5252, 5255, 5522, 5525, 5552, 5555, 22222, 22225, 22252, 22255, 22522, 22525, 22552, 22555, 25222, 25225, 25252, 25255

Offset

1,1

References

M. J. Halm, Three Boxes, Puzzle-M Magazine (Apr. 1987).

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..8190

Mathematica

Flatten[Table[FromDigits/@Tuples[{2, 5}, n], {n, 5}]] (* Vincenzo Librandi, Aug 19 2016 *)

Prog

(Python)
from itertools import product
A072961_list = [int(''.join(a)) for l in range(1, 11) for a in product('25', repeat=l)] # Chai Wah Wu, May 12 2016
(Magma) [n: n in [1..30000] | Set(Intseq(n)) subset {2, 5}]; // Vincenzo Librandi, Aug 19 2016

Crossrefs

Sequence in context: A174143 A298762 A025559 * A249829 A042557 A137097

Adjacent sequences: A072958 A072959 A072960 * A072962 A072963 A072964

Keyword

easy,nonn,base

Author

Michael Joseph Halm, Aug 13 2002

Status

approved