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A121660 Numerator of fraction equal to the continued fraction [4, 6, 9, ..., semiprime(n)]. 2
4, 25, 229, 2315, 32639, 491900, 10362539, 228467758, 5722056489, 149001936472, 4922785960065, 167523724578682, 5868253146213935, 223161143280708212, 8709152841093834203, 400844191833597081550, 19650074552687350830153 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Denominator of fraction equal to the continued fraction [4, 6, 9, ..., semiprime(n)] is A121661. Hence A121660/A121661 is semiprime analogue of A036247/A036248.

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.

CROSSREFS

Cf. A001358, A036247, A036248, A121661.

Sequence in context: A031152 A010845 A087660 * A118835 A194569 A198058

Adjacent sequences:  A121657 A121658 A121659 * A121661 A121662 A121663

KEYWORD

easy,frac,nonn

AUTHOR

Jonathan Vos Post (jvospost3(AT)gmail.com), Aug 14 2006

EXTENSIONS

More terms from Arkadiusz Wesolowski, Jul 03 2011

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Last modified February 17 00:09 EST 2012. Contains 205978 sequences.