id:A109240 - OEIS Search Results

Search: id:A109240

Displaying 1-1 of 1 results found.

page 1

Numbers n such that the concatenation of consecutive increasing numbers beginning with prime(n) and ending with prime(n+1) is semiprime; or n such that A111875(n) is semiprime.

+0
1

12, 16, 31, 55, 74, 84, 86, 93, 108, 114, 133, 161, 164, 170, 200, 211, 218, 224, 231, 242, 252, 271, 287, 301, 347, 358, 449, 450, 505, 520, 556, 576, 597, 621, 622, 629, 632, 657, 667, 703, 716, 733, 756, 767, 782, 788, 789, 813, 814, 834, 850, 852, 882 (list; graph; listen)

	OFFSET	`1,1`
	EXAMPLE	`a(3)=31 because prime(31)=127 and prime(32)=131 and 127128129130131 =` `3*42376043043377.`
	CROSSREFS	`Sequence in context: A070329 A064695 A077617 this_sequence A020740 A086980 A058203` `Adjacent sequences: A109237 A109238 A109239 this_sequence A109241 A109242 A109243`
	KEYWORD	`less,nonn`
	AUTHOR	`Jason Earls (zevi_35711(AT)yahoo.com), Aug 19 2005`
	EXTENSIONS	`More terms from David Wasserman (dwasserm(AT)earthlink.net), May 28 2008`

page 1

Search completed in 0.002 seconds

Last modified September 6 09:40 EDT 2008. Contains 143480 sequences.

AT&T Labs Research