A089987 - OEIS

This site is supported by donations to The OEIS Foundation.

A089987

Primes in the concatenation of consecutive numbers beginning with 2.

2, 23, 23456789, 23456789101112131415161718192021222324252627 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,1`
	COMMENTS	`Sum of reciprocals = 0.5434783035011462065880780409..`
	PROG	`(PARI) concatprime(n, p) = { sr=0; y=""; for(x=p, n, y=concat(Str(y), Str(x)); z=eval(y); if(ispseudoprime(z), print1(z", "); sr+=1./z; ); ); print(); print(sr) }`
	CROSSREFS	`Sequence in context: A114256 A110714 A067837 * A162605 A118812 A054909` `Adjacent sequences: A089984 A089985 A089986 * A089988 A089989 A089990`
	KEYWORD	`nonn,base`
	AUTHOR	`Cino Hilliard (hillcino368(AT)gmail.com), Jan 14 2004`

Content is available under The OEIS End-User License Agreement .

Last modified February 15 20:03 EST 2012. Contains 205852 sequences.