A089437 - OEIS

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A089437

Numbers n such that 4^n + 3 is prime.

1, 2, 3, 6, 8, 9, 14, 15, 42, 114, 195, 392, 555, 852, 1004, 1185, 2001, 2030, 2031, 2276, 8610, 8967, 10362, 11366, 15927, 16514, 17877, 19122, 19898, 27728, 29156, 61275, 102981, 117663, 181560, 239922, 342789 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,2`
	COMMENTS	`The halved even terms of A057732. - R. J. Mathar, Feb 26 2008`
	LINKS	`Table of n, a(n) for n=1..37.`
	EXAMPLE	`4^15 + 3 = 1073741827 a prime number`
	PROG	`(PARI) is(n)=ispseudoprime(4^n+3) \\ Charles R Greathouse IV, Feb 20 2017`
	CROSSREFS	`Cf. A228026 (the actual primes)` `Sequence in context: A111215 A099381 A289943 * A146768 A211370 A122479` `Adjacent sequences: A089434 A089435 A089436 * A089438 A089439 A089440`
	KEYWORD	`nonn`
	AUTHOR	`Herman H. Rosenfeld (herm3(AT)pacbell.net), Dec 28 2003`
	EXTENSIONS	`More terms from Ray Chandler, Dec 30 2003` `More terms from R. J. Mathar, Feb 26 2008` `a(33)-a(38) derived from A057732 by Robert Price, Apr 26 2014`
	STATUS	`approved`

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Last modified December 14 12:04 EST 2019. Contains 329979 sequences. (Running on oeis4.)