A091271 - OEIS

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A091271

Numbers k such that 4*k^2-11 is a prime.

2, 4, 5, 9, 10, 14, 16, 19, 21, 24, 26, 31, 35, 39, 40, 45, 59, 60, 65, 74, 79, 80, 86, 91, 100, 105, 109, 114, 115, 116, 119, 124, 126, 129, 130, 131, 135, 136, 145, 149, 150, 151, 159, 170, 171, 175, 179, 180, 185, 186, 189, 194, 199, 205, 206, 210, 219, 221

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A090696(n)/2.

MAPLE

select(t -> isprime(4*t^2-11), [$2..1000]); # Robert Israel, Jul 10 2018

PROG

(PARI) is(n) = ispseudoprime(4*n^2-11) \\ Felix Fröhlich, Jul 10 2018

(GAP) Filtered([2..230], n->IsPrime(4*n^2-11)); # Muniru A Asiru, Jul 10 2018

CROSSREFS

A091272 gives primes, A091273 gives prime index.

Sequence in context: A089221 A347877 A167180 * A063985 A050052 A071349

Adjacent sequences: A091268 A091269 A091270 * A091272 A091273 A091274

KEYWORD

nonn

AUTHOR

Ray Chandler, Dec 27 2003

EXTENSIONS

Offset changed by Robert Israel, Jul 10 2018

STATUS

approved