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A289182 Positions of odd semiprimes in A001358. 13
3, 6, 7, 9, 11, 13, 15, 17, 18, 19, 20, 23, 24, 26, 28, 30, 31, 32, 34, 36, 37, 39, 40, 42, 43, 44, 46, 48, 49, 51, 53, 54, 56, 57, 59, 60, 61, 63, 65, 66, 68, 69, 71, 72, 74, 75, 77, 78, 79, 80, 81, 83, 85, 86, 89, 90, 91, 92, 94, 95, 97, 98 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Complement to A115392.

LINKS

Table of n, a(n) for n=1..62.

FORMULA

a(n) ~ n. - Charles R Greathouse IV, Jul 02 2017

MATHEMATICA

sp=Select[Range[4, 1000], 2==PrimeOmega[#]&]; Flatten[Position[Mod[sp, 2], 1]]

PROG

(PARI) lista(nn) = vsp = select(x->(bigomega(x)==2), vector(nn, k, k)); select(x->(x%2), vsp, 1); \\ Michel Marcus, Jul 02 2017

CROSSREFS

Cf. A001358, A115392.

Sequence in context: A221264 A026415 A026406 * A188974 A047558 A160217

Adjacent sequences:  A289179 A289180 A289181 * A289183 A289184 A289185

KEYWORD

nonn

AUTHOR

Zak Seidov, Jun 27 2017

STATUS

approved

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Last modified June 22 00:39 EDT 2021. Contains 345367 sequences. (Running on oeis4.)