id:A056906 - OEIS Search Results

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Numbers n where 36n^2+5 is prime.

+0
6

0, 1, 2, 6, 8, 12, 13, 16, 19, 21, 27, 28, 33, 34, 41, 43, 49, 56, 57, 62, 69, 72, 76, 77, 82, 84, 86, 89, 92, 96, 98, 99, 104, 111, 119, 121, 126, 128, 131, 132, 133, 134, 139, 142, 146, 148, 153, 159, 166, 168, 169, 173, 174 (list; graph; listen)

	OFFSET	`0,3`
	COMMENT	`Except for a(0), a(n) is never a multiple of 5.`
	FORMULA	`a(n) =sqrt(A056905(n)-5)/6`
	EXAMPLE	`a(2)=2 since 36*2^2+5=149 which is prime (as well as being half a square)`
	CROSSREFS	`This sequence and formula generate all primes of the form k^2+5, i.e. A056905. Except for the first term, this sequence is a subsequence of A047201. Cf. A056900, A056902.` `Sequence in context: A130205 A054067 A064212 this_sequence A047238 A111367 A105059` `Adjacent sequences: A056903 A056904 A056905 this_sequence A056907 A056908 A056909`
	KEYWORD	`nonn`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Jul 07 2000`

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Last modified November 24 23:16 EST 2009. Contains 167481 sequences.

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