id:A143394 - OEIS Search Results

Search: id:A143394

Displaying 1-1 of 1 results found.

page 1

Least prime a(n) such that a(n)*(a(n)+p(n))-1 and a(n)*(a(n)+p(n))+1 are twin primes or 0 if not such prime exist, with p(i)=i-th prime.

+0
2

0, 3, 0, 2, 3, 2, 3, 2, 109, 1291, 3, 557, 211, 3, 3, 7, 7, 3, 2, 13, 2, 5, 43, 97, 2, 3, 149, 43, 5, 3, 5, 13, 3, 2, 7, 3, 5, 197, 13, 73, 7, 11, 229, 23, 3, 5, 3, 23, 13, 2, 19, 7, 5, 109, 283, 67, 7, 3, 11, 13, 2, 43, 2, 19, 233, 7, 1061, 3, 3, 149, 43, 421, 11, 113, 29, 7, 991, 41, 61 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`no first of twin primes of the form a(a+2)-1 for a prime` `only one first of twin primes of the form a(a+3)-1 for a=3` `no first of twin primes of the form a*(a+5)-1 for a prime`
	LINKS	`Pierre CAMI, Table of n, a(n) for n = 1..12250`
	EXAMPLE	`3*(3+3)-1=17 prime so a(2)=3 as p(2)=3 and 17 and 19 twin primes`
	CROSSREFS	`Cf. A143393.` `Sequence in context: A013307 A119493 A032531 this_sequence A112455 A001608 A159977` `Adjacent sequences: A143391 A143392 A143393 this_sequence A143395 A143396 A143397`
	KEYWORD	`nonn`
	AUTHOR	`Pierre CAMI (pierrecami(AT)tele2.fr), Aug 12 2008`

page 1

Search completed in 0.002 seconds

Last modified December 16 17:18 EST 2009. Contains 170825 sequences.

AT&T Labs Research