

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 bitwisexored 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
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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 bitwiseXOR of exponents 3, 2 and 1 ("11", "10" and "01" in binary) results zero.


PROG

(Scheme, with Antti Karttunen's IntSeqlibrary)
(define A268390 (ZEROPOS 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



