A182342 Primes of the form n*2^n + 5.

5, 7, 13, 29, 389, 2053, 49157, 106501, 402653189, 1744830469, 2473901162501, 184717953466373, 774056185954309, 31057439705591620336669228531717, 70745044697537026438728012485623813

Offset

1,1

Comments

These are similar to the Woodall primes, A050918, which are primes of the form n*2^n - 1.

Links

Table of n, a(n) for n=1..15.

Example

5 = 0*2^0 + 5; 7 = 1*2^1 + 5; 13 = 2*2^2 + 5; 29 = 3*2^3 + 5; 389 = 6*2^6 + 5

Maple

#choose N large, then S is the desired set
f:=n->n*2^n + 5:
S:={}:
for n from 0 to N do if(isprime(f(n))) then S:=S union {f(n)}: fi: od

Crossrefs

Cf. A050918, A182354, A182352, A182353.

Sequence in context: A158294 A090610 A230115 * A178648 A241859 A293059

Adjacent sequences: A182339 A182340 A182341 * A182343 A182344 A182345

Keyword

nonn

Author

Patrick Devlin, Apr 25 2012

Status

approved