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A112735
Exclusionary squares.
3
4, 9, 16, 49, 64, 81, 289, 324, 576, 841, 1156, 1444, 1521, 2209, 2809, 2916, 3249, 3364, 3481, 3844, 4489, 5184, 6241, 7056, 8464, 8836, 24649, 24964, 29929, 34969, 36864, 37636, 43681, 56169, 56644, 61009, 64009, 66049, 67081, 94249, 98596
OFFSET
1,1
COMMENTS
An exclusionary square m^2 is one sharing no digit in common with its root m made up of distinct digits. The associated root is given by A112736.
The largest term is 639172^2 = 408540845584; and is the seq. because the intersection of {1,2,3,6,7,9} & {0, 4, 5, 8} = {}. Number of terms < 10^n: 2, 6, 10, 26, 41, 71, 84, 121, 129, 140, 141, 142. - Robert G. Wilson v, Apr 03 2009
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
Robert G. Wilson v, Table of n, a(n) for n = 1..142 (full sequence)
MATHEMATICA
fQ[n_] := Intersection[ IntegerDigits[n], IntegerDigits[n^2]] == {}; Select[ Range@ 330, fQ@# &]^2 (* Robert G. Wilson v, Apr 03 2009 *)
CROSSREFS
Cf. A112322.
Sequence in context: A034378 A062387 A029784 * A059931 A027382 A164840
KEYWORD
nonn,base,fini,full
AUTHOR
Lekraj Beedassy, Sep 16 2005
EXTENSIONS
Corrected and extended by Don Reble, Nov 22 2006
STATUS
approved