A207017 - OEIS

A207017

Numbers m for which there exists a number 1<k=k(m)<m, such that m is in the sequence: b_1 = k, b_(n+1) = b_n<+>k, where operation <+> is defined in A206853.

4, 7, 9, 11, 13, 14, 16, 18, 21, 22, 24, 26, 28, 31, 33, 35, 39, 41, 44, 46, 47, 49, 50, 53, 55, 56, 57, 59, 61, 62, 63, 66, 70, 73, 79, 82, 83, 84, 89, 93, 94, 96, 97, 102, 104, 110, 111, 112, 115, 116, 118, 120, 121, 122, 124, 125, 126, 127, 129, 131

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OFFSET

1,1

COMMENTS

It is natural to call terms of the sequence "Hamming composite numbers" and to say that m is "H-divisible" by k.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..10000

EXAMPLE

127 = b_21 for k=2, b_16 for k=4 and b_8 for k=5. Thus 127 is H-divisible by 2, 4 and 5 (and only by them).

CROSSREFS

Cf. A000225, A205509, A205510, A205511, A205302, A205649, A205533, A122565, A206853, A207016.

Sequence in context: A007656 A159619 A272454 * A174724 A267873 A310943

Adjacent sequences: A207014 A207015 A207016 * A207018 A207019 A207020

KEYWORD

nonn,base

AUTHOR

Vladimir Shevelev, Feb 14 2012

STATUS

approved