OFFSET
0,2
COMMENTS
LINKS
Hans Havermann, Table of n, a(n) for n = 0..10000
MATHEMATICA
a[0] = 0; a[n_] := a[n] = Block[{k = 1, idm = IntegerDigits@ a[n - 1], t = a@# & /@ Range[n - 1]}, Label[ start]; While[ MemberQ[t, k], k++]; While[ Select[ Permutations[ Join[idm, IntegerDigits[ k]]], #[[1]] != 0 && IntegerQ[ Sqrt[ FromDigits[ #]]] &] == {}, k++; Goto[ start]]; k]; Array[a, 100, 0] (* Robert G. Wilson v, Nov 17 2013 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Nov 17 2013, based on a posting to the Sequence Fans Mailing List by Andrew Weimholt, Nov 12 2013
EXTENSIONS
Corrected and extended by Hans Havermann, Nov 17 2013
More terms added (from b-file) by Jon E. Schoenfield, Dec 22 2013
STATUS
approved