A109757 - OEIS

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A109757

Numbers n such that (10's complement factorial of n) + 1 is semiprime.

1, 3, 6, 14, 20, 21, 26, 34, 37, 39, 40, 47, 51, 54, 61, 62, 72, 74, 77, 82, 83, 86, 113, 115, 118, 127, 139, 179 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	PROG	`(PARI) comp(n)=10^#Str(n)-n` `is(n)=bigomega(prod(k=1, n, comp(k))+1)==2 \\ Charles R Greathouse IV, Jul 10 2011`
	CROSSREFS	`Cf. A110396, A109616.` `Sequence in context: A083356 A096337 A175318 * A075189 A200823 A093866` `Adjacent sequences: A109754 A109755 A109756 * A109758 A109759 A109760`
	KEYWORD	`nonn,base`
	AUTHOR	`Jason Earls (zevi_35711(AT)yahoo.com), Aug 12 2005`
	EXTENSIONS	`More terms from Sean A. Irvine (sairvin(AT)xtra.co.nz), Jul 10 2011`

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Last modified February 14 05:09 EST 2012. Contains 205570 sequences.