id:A100318 - OEIS Search Results

Search: id:A100318

Displaying 1-1 of 1 results found.

page 1

Numbers n such that at least one of n-1 and n+1 is composite.

+0
3

3, 5, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 81 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`All odd numbers > 1 occur in this sequence. For the subsequence of even terms, see A100319.`
	PROGRAM	`(PARI) for(n=3, 200, if(isprime(n-1)+isprime(n+1)<=1, print1(n, ", ")))`
	CROSSREFS	`Cf. A100317 (exactly one of n-1 and n+1 is prime/composite), A100319.` `Sequence in context: A137203 A102890 A008520 this_sequence A167707 A131903 A141114` `Adjacent sequences: A100315 A100316 A100317 this_sequence A100319 A100320 A100321`
	KEYWORD	`nonn`
	AUTHOR	`Rick L. Shepherd (rshepherd2(AT)hotmail.com), Nov 13 2004`

page 1

Search completed in 0.002 seconds

Last modified November 25 08:46 EST 2009. Contains 167481 sequences.

AT&T Labs Research