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A030153 Numbers k such that in k and k^2 the parity of digits alternates. 4
0, 1, 2, 3, 4, 5, 6, 7, 9, 16, 23, 27, 36, 69, 74, 81, 96, 127, 181, 187, 296, 874, 2327, 2369, 2723, 2727, 2763, 3816, 4589, 5874, 6563, 6589, 6727, 8323, 10181, 12723, 18163, 18587, 21236, 21274, 29236, 29274, 30127, 43296, 52361, 78163, 87616 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..1226 (derived from A030154 b-file)

MATHEMATICA

altQ[n_] := n < 10 || Union[Total /@ Partition[ Mod[ IntegerDigits@n, 2], 2, 1]] == {1}; Select[ Range[0, 10^5], altQ[#] && altQ[#^2] &] (* Giovanni Resta, Aug 16 2018 *)

CROSSREFS

Cf. A030151, A030152, A030154, A030156, A030157, A030158.

Sequence in context: A030287 A271950 A263482 * A039126 A083376 A044957

Adjacent sequences:  A030150 A030151 A030152 * A030154 A030155 A030156

KEYWORD

nonn,base

AUTHOR

Patrick De Geest

STATUS

approved

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Last modified December 4 13:29 EST 2021. Contains 349526 sequences. (Running on oeis4.)