A295299 Numbers k such that the sum of the divisors (A000203) and the binary weight of k (A000120) have different parity.

7, 9, 11, 13, 14, 18, 19, 21, 22, 26, 28, 31, 35, 36, 37, 38, 41, 42, 44, 47, 52, 55, 56, 59, 61, 62, 67, 69, 70, 72, 73, 74, 76, 79, 82, 84, 87, 88, 91, 93, 94, 97, 103, 104, 107, 109, 110, 112, 115, 117, 118, 122, 124, 127, 131, 133, 134, 137, 138, 140, 143, 144, 145, 146, 148, 151, 152, 155, 157, 158, 161, 164, 167, 168, 169

Offset

1,1

Comments

Numbers k for which A010059(k) = A053866(k).

This sequence is the union of all terms of A028982 (squares and twice squares) that are evil (A001969), and all odious numbers (A000069) that are neither a square or twice a square. See also A231431, A235001.

This is a subsequence of A004169, numbers k such that phi(k) is not a power of 2. See comment in A295298 for the reason. - Antti Karttunen, Nov 27 2017

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to binary expansion of n

Mathematica

Select[Range@ 169, UnsameQ @@ Map[EvenQ, {DivisorSigma[1, #], DigitCount[#, 2, 1]}] &] (* Michael De Vlieger, Nov 26 2017 *)

Crossrefs

Complement of A295298.

Subsequence of A004169.

Cf. A000069, A001969, A000120, A000203, A010059, A028982, A053866, A231431, A235001, A295297 (characteristic function).

Sequence in context: A167377 A360796 A004169 * A066669 A059808 A020742

Adjacent sequences: A295296 A295297 A295298 * A295300 A295301 A295302

Keyword

nonn

Author

Antti Karttunen, Nov 26 2017

Status

approved