A183059 Cyclops primes p such that 2p+1 is also a Cyclops prime.

12011, 12041, 13049, 18041, 21011, 22013, 28019, 29021, 29033, 31019, 33023, 37013, 37049, 38039, 42023, 43013, 48029, 1110269, 1120349, 1120481, 1130273, 1130429, 1140143, 1140311, 1140341, 1140383, 1140413, 1140449, 1160129, 1160213, 1160429, 1170173, 1170329, 1170443

Offset: 1

Author

Omar E. Pol, Dec 25 2010

Keywords

• nonn
• base
• less

Comments

Primes p such that both p and 2p+1 are Cyclops primes A134809.

By definition all terms are also Sophie Germain primes A005384.

Examples

			a(1) = 12011 is in the sequence because 12011 is a Cyclops prime A134809 and 2*12011+1 = 24023 is also a Cyclops prime.
		

Crossrefs

Cf. A005384, A134808, A134809, A183058.

Programs

Maple

isA134808 := proc(n) local dgs,ndgs; dgs := convert(n,base,10) ; mdg := (nops(dgs)+1)/2 ; if type(nops(dgs),'even') then false; elif n = 0 then true; else if op(mdg,dgs) <> 0 then false; else if mul(op(k,dgs),k=1..mdg-1) =0 or mul(op(k,dgs),k=mdg+1..nops(dgs)) = 0 then false; else true; end if; end if; end if; end proc:
isA134809 := proc(n) isprime(n) and isA134808(n) ; end proc:
isA183059 := proc(n) isA134809(n) and isA134809(2*n+1) ; end proc:
for n from 0 to 1200000 do if isA183059(n) then printf("%d,",n); end if; end do: # R. J. Mathar, Jan 05 2011