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A121660
Duplicate of A118835.
2
4, 25, 229, 2315, 32639, 491900, 10362539, 228467758, 5722056489, 149001936472, 4922785960065, 167523724578682, 5868253146213935, 223161143280708212, 8709152841093834203, 400844191833597081550, 19650074552687350830153
OFFSET
1,1
COMMENTS
Previous name was: Numerator of fraction equal to the continued fraction [4, 6, 9, ..., semiprime(n)].
Apparently the same as A118835. - Georg Fischer, Oct 03 2018
LINKS
FORMULA
Numerator of fraction equal to the continued fraction [4, 6, 9, ..., A001358(n)].
EXAMPLE
a(1) = numerator of 4 = 4.
a(2) = numerator of 4 + 1/6 = numerator of 25/6 = 25.
a(3) = numerator of 4 + 1/(6+1/9) = numerator of 229/55 = 229.
a(10) = numerator of 4+1/(6+1/(9+1/(10+ 1/(14+1/(15+ 1/(21+1/(22+1/(25+1/(26))))))))) = numerator of 149001936472/35786212191 = 149001936472.
MAPLE
SP:= select(t -> numtheory:-bigomega(t)=2, [$4..100]):
seq(numer(numtheory:-cfrac(SP[1..n])), n=1..nops(SP)); # Robert Israel, Jul 10 2018
MATHEMATICA
Module[{nn=70, sps}, sps=Select[Range[nn], PrimeOmega[#]==2&]; Table[Numerator[ FromContinuedFraction[ Take[sps, n]]], {n, Length[sps]}]] (* Harvey P. Dale, Jan 09 2024 *)
CROSSREFS
Sequence in context: A031152 A010845 A087660 * A118835 A365053 A224080
KEYWORD
dead
AUTHOR
Jonathan Vos Post, Aug 14 2006
EXTENSIONS
More terms from Arkadiusz Wesolowski, Jul 03 2011
STATUS
approved