A109311 - OEIS

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A109311

Numbers n such that sum of n-th and (n+1)-st semiprimes is a square=q^2.

6, 17, 58, 78, 89, 122, 187, 219, 229, 278, 313, 353, 367, 552, 589, 966, 1162, 1264, 1530, 1637, 1745, 1928, 2343, 2443, 2540 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	FORMULA	`sp(n)+sp(n+1)=q^2, sp(n)=n-th semiprime.`
	EXAMPLE	`6 is ok because sp(6)=15, sp(7)=21, 15+21=36=6^2, sp(n)=A001358(n)=n-th semiprime.`
	CROSSREFS	`Values of q: A109312. Cf. A001358 = semiprimes, A092191 = numbers n such that sum of n-th and (n+1)-st semiprimes is a semiprime.` `Sequence in context: A199113 A088016 A010330 * A151350 A195741 A006758` `Adjacent sequences: A109308 A109309 A109310 * A109312 A109313 A109314`
	KEYWORD	`nonn`
	AUTHOR	`Zak Seidov (zakseidov(AT)yahoo.com), Jun 27 2005`

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Last modified February 14 11:36 EST 2012. Contains 205623 sequences.