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A268390 Positions of zeros in A268387: numbers n such that when the exponents e_1 .. e_k in their prime factorization n = p_1^e_1 * ... * p_k^e_k are bitwise-xored together, the result is zero. 5
1, 6, 10, 14, 15, 21, 22, 26, 33, 34, 35, 36, 38, 39, 46, 51, 55, 57, 58, 62, 65, 69, 74, 77, 82, 85, 86, 87, 91, 93, 94, 95, 100, 106, 111, 115, 118, 119, 122, 123, 129, 133, 134, 141, 142, 143, 145, 146, 155, 158, 159, 161, 166, 177, 178, 183, 185, 187, 194, 196, 201, 202, 203, 205, 206, 209, 210 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

EXAMPLE

1 has an empty factorization, and as XOR of an empty set is zero, 1 is included.

6 = 2^1 * 3^1 and as XOR(1,1) = 0, 6 is included.

30 = 2^1 * 3^1 * 5^1 is NOT included, as XOR(1,1,1) = 1.

360 = 2^3 * 3^2 * 5^1 is included, as the bitwise-XOR of exponents 3, 2 and 1 ("11", "10" and "01" in binary) results zero.

PROG

(Scheme, with Antti Karttunen's IntSeq-library)

(define A268390 (ZERO-POS 1 1 A268387))

CROSSREFS

Cf. A268387.

Cf. A006881, A238748 (subsequences. See the latter for even more subsequences).

Differs from A238748 for the first time at n=115, where a(115) = 360, a value missing from A238748.

Sequence in context: A325259 A320911 A238748 * A265693 A211484 A006881

Adjacent sequences:  A268387 A268388 A268389 * A268391 A268392 A268393

KEYWORD

nonn,base

AUTHOR

Antti Karttunen, Feb 05 2016

STATUS

approved

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Last modified August 22 02:44 EDT 2019. Contains 326169 sequences. (Running on oeis4.)