

A268388


"FermiDirac composites": numbers n for which A064547(n) > 1.


5



6, 8, 10, 12, 14, 15, 18, 20, 21, 22, 24, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 50, 51, 52, 54, 55, 56, 57, 58, 60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 82, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 100, 102, 104, 105, 106, 108, 110, 111, 112, 114, 115, 116, 117, 118, 119, 120
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OFFSET

1,1


LINKS

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


EXAMPLE

6 = 2^1 * 3^1 is present, as there are altogether two 1bits in the exponents (1 and 1 also in binary), which is more than one.
64 = 2^6 is present, as the binary representation of 6 is "110", which contains more than one 1bit. This is also the first term not present in A139118.


PROG

(Scheme, with Antti Karttunen's IntSeqlibrary)
(define A268388 (MATCHINGPOS 1 1 (lambda (n) (> (A064547 n) 1))))
(PARI) isok(n) = my(f = factor(n)[, 2]); sum(k=1, #f, hammingweight(f[k])) > 1; \\ Michel Marcus, Feb 10 2016


CROSSREFS

Subsequence of A002808.
Cf. A050376 (complement without 1).
Cf. A064547.
Cf. A176699 (subsequence), A000379 (also subsequence, without the initial 1).
Different from A139118.
Sequence in context: A080731 A080257 A050199 * A139118 A089229 A123240
Adjacent sequences: A268385 A268386 A268387 * A268389 A268390 A268391


KEYWORD

nonn


AUTHOR

Antti Karttunen, Feb 09 2016, after Vladimir Shevelev's Apr 2010 comment in A176699.


STATUS

approved



