A113318 Numbers whose biquadrates (fourth powers) are exclusionary.

2, 3, 4, 7, 8, 9, 24, 27, 28, 32, 42, 52, 53, 58, 59, 67, 89, 93, 203, 258, 284, 324, 329, 832, 843, 2673

Offset

1,1

Comments

The number m with no repeated digits has an exclusionary fourth power m^4 if the latter is made up of digits not appearing in m. Is a subsequence of A111116. Conjectured to be complete. For the corresponding exclusionary biquadrates m^4, see A113317.

References

H. Ibstedt, Solution to Problem 2623, "Exclusionary Powers", pp. 346-9, Journal of Recreational Mathematics, Vol. 32 No.4 2003-4 Baywood NY.

Links

Table of n, a(n) for n=1..26.

Mathematica

ebQ[n_]:=Max[DigitCount[n]]==1&&Intersection[IntegerDigits[n], IntegerDigits[ n^4]]=={}; Select[Range[3000], ebQ] (* Harvey P. Dale, Aug 21 2013 *)

Crossrefs

Sequence in context: A059930 A125965 A111116 * A056033 A302123 A286337

Adjacent sequences: A113315 A113316 A113317 * A113319 A113320 A113321

Keyword

base,nonn,fini

Author

Lekraj Beedassy, Oct 26 2005

Status

approved