A182217 Primes p = prime(n) such that there is k>0 for which prime(n+k) = prime(n) + 4^(k-1).

2, 3, 43, 73, 151, 157, 163, 181, 277, 337, 367, 373, 433, 487, 601, 631, 643, 727, 757, 811, 823, 937, 967, 1093, 1213, 1471, 1483, 1543, 1567, 1693, 1873, 2083, 2137, 2281, 2341, 2383, 2647, 2671, 2953, 3307, 3313, 3517, 3607, 3847, 4003, 4441, 4447

Offset

1,1

Links

Table of n, a(n) for n=1..47.

Example

2=prime(1+1)-4^(1-1)=3-1, 3=prime(2+2)-4^(2-1)=7-4, 43=prime(14+3)-4^(3-1)=59-16, 73=prime(21+3)-4^(3-1)=89-16.

Prog

(PARI) is_A182217(p)={isprime(p) || return; my(q=p); for(k=0, 9, p+4^k==(q=nextprime(q+1)) & return(1))}  \\ M. F. Hasler, May 20 2012
(PARI) for(n=1, 9999, for(k=1, 9, prime(n+k)-prime(n)==4^(k-1)&!print1(prime(n)", ")&break))  \\ M. F. Hasler, May 20 2012

Crossrefs

Cf. A001223.

Sequence in context: A237414 A051099 A162712 * A233314 A062581 A077520

Adjacent sequences: A182214 A182215 A182216 * A182218 A182219 A182220

Keyword

nonn

Author

Gerasimov Sergey, Apr 19 2012

Status

approved