A134854 Least prime of the form 1 + p*2^n, where p is an odd prime.

7, 13, 41, 113, 97, 193, 641, 769, 11777, 13313, 59393, 12289, 40961, 114689, 163841, 2424833, 6946817, 786433, 5767169, 7340033, 23068673, 155189249, 595591169, 1224736769, 167772161, 469762049, 2281701377, 3489660929, 12348030977

Offset

1,1

Comments

a(n) least prime such that A098006(pi(a(n))) = 2^(n-1). See A134855 for the values of p.

Links

T. D. Noe, Table of n, a(n) for n=1..1000

Mathematica

Table[Select[1+2^n*Prime[Range[2, 100]], PrimeQ, 1][[1]], {n, 41}]

Crossrefs

Sequence in context: A056249 A107207 A045464 * A330671 A097444 A241718

Adjacent sequences: A134851 A134852 A134853 * A134855 A134856 A134857

Keyword

nonn

Author

T. D. Noe, Nov 13 2007

Status

approved