A102393 A wicked evil sequence.

1, 0, 0, 4, 0, 6, 7, 0, 0, 10, 11, 0, 13, 0, 0, 16, 0, 18, 19, 0, 21, 0, 0, 24, 25, 0, 0, 28, 0, 30, 31, 0, 0, 34, 35, 0, 37, 0, 0, 40, 41, 0, 0, 44, 0, 46, 47, 0, 49, 0, 0, 52, 0, 54, 55, 0, 0, 58, 59, 0, 61, 0, 0, 64, 0, 66, 67, 0, 69, 0, 0, 72, 73, 0, 0, 76, 0, 78, 79, 0, 81, 0, 0, 84, 0, 86

Offset: 0

Author

Paul Barry, Jan 06 2005

Keywords

• easy
• nonn

Comments

Elements of A026147 (evil numbers plus one) appear at positions indexed by the evil numbers A001969, 0 otherwise. A000027(n) = A102393(n) + A102394(n).

The following sequences all appear to have the same parity: A003071, A029886, A061297, A092524, A093431, A102393, A104258, A122248, A128975. - Jeremy Gardiner, Dec 28 2008

Links

• Tanya Khovanova, There are no coincidences, arXiv preprint 1410.2193 [math.CO], 2014.

Crossrefs

Cf. A000027, A000120, A001969, A010060, A026147, A102391, A102393, A102394.

Cf. A003071, A029886, A061297, A092524, A093431, A104258, A122248, A128975.

Programs

Mathematica

a[n_] := If[EvenQ @ DigitCount[n, 2, 1], n + 1, 0]; Array[a, 100, 0] (* Amiram Eldar, Aug 02 2020 *)

Formula

a(n) = (n+1)(1+(-1)^A000120(n))/2.

a(n) = (n+1)(1+(-1)^A010060(n))/2.