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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..10000

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

Cf. A030151, A030152, A030155, A030157, A030158.

Sequence in context: A016754 A110487 A259417 * A192775 A318737 A246331

Adjacent sequences:  A030153 A030154 A030155 * A030157 A030158 A030159

KEYWORD

nonn,base

AUTHOR

Patrick De Geest

EXTENSIONS

Offset changed by Giovanni Resta, Aug 16 2018

STATUS

approved

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Last modified November 12 19:25 EST 2019. Contains 329078 sequences. (Running on oeis4.)