A128691 - OEIS

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A128691

Numbers of the form 2^k*p, where 1 <= k <= 8 and p is a prime > 2.

6, 10, 12, 14, 20, 22, 24, 26, 28, 34, 38, 40, 44, 46, 48, 52, 56, 58, 62, 68, 74, 76, 80, 82, 86, 88, 92, 94, 96, 104, 106, 112, 116, 118, 122, 124, 134, 136, 142, 146, 148, 152, 158, 160, 164, 166, 172, 176, 178, 184, 188, 192, 194, 202, 206, 208, 212, 214, 218, 224

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OFFSET

1,1

COMMENTS

Subsequence of A100368 (numbers of the form 2^k*p, where k>0 and p is an odd prime); 1536 = 2^9*3 is the smallest term of A100368 that is not in the present sequence.

Auxiliary sequence for A128645 which gives the number of groups of order a(n).

LINKS

Klaus Brockhaus, Table of n, a(n) for n=1..10000

EXAMPLE

40 = 2^3*5 is a term.

PROG

(Magma) [ n: n in [1..225] | #t eq 2 and t[1, 1] eq 2 and t[1, 2] le 8 and t[2, 2] eq 1 where t is Factorization(n) ];

CROSSREFS

Cf. A100368, A128645.

Sequence in context: A088829 A036348 A100368 * A359875 A028919 A325231

Adjacent sequences: A128688 A128689 A128690 * A128692 A128693 A128694

KEYWORD

nonn

AUTHOR

Klaus Brockhaus, Mar 21 2007

STATUS

approved