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A112321 Least n-digit number such that its square is exclusionary, or 0 if no such number exists. 3
2, 17, 157, 1547, 15094, 203879, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

m has an exclusionary square if m consists of distinct digits and m^2 is made up only of digits not appearing in m.

a(10) = 0 since 10-digit numbers either use all digits or at least one digit more than once; a(n) = 0 for n > 10 since numbers with more than 10 digits use at least one digit more than once.

REFERENCES

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

LINKS

Table of n, a(n) for n=1..9.

CROSSREFS

Cf. A112322 (corresponding squares), A110815.

Sequence in context: A176934 A126037 A241135 * A276198 A178806 A197864

Adjacent sequences:  A112318 A112319 A112320 * A112322 A112323 A112324

KEYWORD

nonn,base,fini

AUTHOR

Lekraj Beedassy and Klaus Brockhaus, Sep 08 2005

STATUS

approved

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Last modified September 26 05:09 EDT 2017. Contains 292502 sequences.