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A050526 Primes of form 5*2^n+1. 7
11, 41, 641, 40961, 163841, 167772161, 2748779069441, 180143985094819841, 188894659314785808547841, 193428131138340667952988161, 850705917302346158658436518579420528641 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Muniru A Asiru, Table of n, a(n) for n = 1..12

Ray Ballinger, Wilfried Keller, List of primes k*2^n + 1 for k < 300

Wikipedia, Proth's theorem

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

FORMULA

a(n) = A083575(A002254(n)). - Michel Marcus, Mar 29 2018

MAPLE

a:=(n, k)->`if`(isprime(k*2^n+1), k*2^n+1, NULL):

seq(a(n, 5), n=1..127); # Martin Renner, Mar 05 2018

PROG

(MAGMA) [a: n in [1..200] | IsPrime(a) where a is 5*2^n + 1]; // Vincenzo Librandi, Mar 06 2018

(GAP) Filtered(List([1..270], n->5*2^n + 1), IsPrime); # Muniru A Asiru, Mar 06 2018

(PARI) lista(nn) = {for(k=1, nn, if(ispseudoprime(p=5*2^k+1), print1(p, ", "))); } \\ Altug Alkan, Mar 29 2018

CROSSREFS

For the corresponding exponents n see A002254.

Cf. A019434, A039687, A050527, A050528, A050529, A195745, A300406, A300407, A300408.

Sequence in context: A068840 A082424 A153173 * A257967 A104118 A159561

Adjacent sequences:  A050523 A050524 A050525 * A050527 A050528 A050529

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 29 1999

STATUS

approved

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Last modified October 19 04:40 EDT 2019. Contains 328211 sequences. (Running on oeis4.)