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A122500 Semiprimes in A006054. 0
25, 183922, 413269, 2086561, 268550439, 77664004259, 1286498670037058, 835992504648428541, 69918194872608910320341, 157104757807495406675035, 353011186440414668176111, 13139449230370726052061293111 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..12.

MATHEMATICA

semiPrimeQ[n_Integer] := Plus @@ Last /@ FactorInteger[n] == 2; s = CoefficientList[ Series[x/(x^3 - x^2 - 2*x + 1), {x, 0, 100}], x]; Select[s, SemiprimeQ@# &]

Select[LinearRecurrence[{2, 1, -1}, {0, 0, 1}, 100], PrimeOmega[#]==2&] (* Harvey P. Dale, Aug 21 2013 *)

CROSSREFS

Cf. A006054, A006053.

Sequence in context: A211600 A068737 A151649 * A251362 A196520 A228536

Adjacent sequences:  A122497 A122498 A122499 * A122501 A122502 A122503

KEYWORD

nonn

AUTHOR

Roger L. Bagula and Gary W. Adamson, Sep 15 2006

EXTENSIONS

Edited by N. J. A. Sloane, Serp 17 2006

More terms from Robert G. Wilson v, Sep 18 2006

STATUS

approved

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Last modified February 19 10:03 EST 2020. Contains 332041 sequences. (Running on oeis4.)