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A030156
Odd squares in which parity of digits alternates.
4
1, 9, 25, 49, 81, 121, 169, 361, 529, 729, 961, 4761, 6561, 12321, 12769, 14161, 16129, 18769, 32761, 34969, 56169, 72361, 74529, 76729, 78961, 96721, 212521, 214369, 290521, 436921, 452929, 458329, 474721, 670761, 690561, 1038361
OFFSET
1,2
LINKS
MATHEMATICA
altQ[n_] := n < 10 || Union[Total /@ Partition[ Mod[ IntegerDigits@n, 2], 2, 1]] == {1}; Select[ Range[1, 2000, 2]^2, altQ[#] &] (* Giovanni Resta, Aug 16 2018 *)
CROSSREFS
KEYWORD
nonn,base
EXTENSIONS
Offset changed by Giovanni Resta, Aug 16 2018
STATUS
approved