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A351897

Numbers that in factorial-base representation have digits with an alternating parity.

0, 1, 2, 5, 7, 11, 14, 19, 23, 26, 38, 55, 59, 67, 71, 74, 86, 103, 107, 115, 119, 127, 131, 139, 143, 175, 179, 187, 191, 223, 227, 235, 239, 266, 278, 314, 326, 367, 371, 379, 383, 415, 419, 427, 431, 463, 467, 475, 479, 506, 518, 554, 566, 607, 611, 619, 623

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OFFSET

1,3

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..20477 (terms below 10!)

EXAMPLE

7 is a term since its factorial-base representation is 101 and the parities of its digits are odd, even, odd.

MATHEMATICA

max = 7; q[n_] := AllTrue[Differences@ Mod[IntegerDigits[n, MixedRadix[Range[max, 2, -1]]], 2], # != 0 &]; Select[Range[0, 1000], q]

CROSSREFS

Cf. A007623.

Similar sequences: A000975 (binary), A030141 (decimal), A033068 (ternary), A179970 (quaternary).