id:A087371 - OEIS Search Results

Search: id:A087371

Displaying 1-1 of 1 results found.

page 1

Smallest k such that 10^k + 2n-1 is a prime >10, or 0 if no such k exists. Index of the smallest power of 10 which when increased by the n-th odd number yields a prime.

+0
2

1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 2, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 2, 1, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 3, 2, 0, 0, 1, 0, 1, 2, 0, 1, 1, 0, 2, 0, 0, 1, 1, 0, 0, 1, 0, 2, 1, 0, 1, 4, 0, 1, 0, 0, 1, 1, 0, 0, 2, 0, 1, 1, 0, 1, 1, 0, 2, 0, 0, 6, 1, 0, 0, 2, 0 (list; graph; listen)

	OFFSET	`1,20`
	COMMENT	`Most of the terms are 0, 1 or 2. Subsidiary sequence: Index of the first occurrence of n. Conjecture: There exists a finite M such that a(n) < M for all n.`
	EXAMPLE	`a(10) = 1 as 10^1 + 19 = 29 is a prime.`
	CROSSREFS	`Adjacent sequences: A087368 A087369 A087370 this_sequence A087372 A087373 A087374` `Sequence in context: A113687 A071006 A080843 this_sequence A112762 A117154 A074941`
	KEYWORD	`nonn`
	AUTHOR	`Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 09 2003`
	EXTENSIONS	`More terms from David Wasserman (wasserma(AT)spawar.navy.mil), May 24 2005`

page 1

Search completed in 0.002 seconds

Last modified October 6 16:13 EDT 2008. Contains 144667 sequences.

AT&T Labs Research