A174042 Places n for which A046132(n) and A006512(n) is a twin prime pair.

1, 9, 10, 24, 28, 67, 195, 361, 362, 382, 459, 462, 470, 759, 765, 766, 794, 864, 869, 909, 1189, 1300, 1303, 1374, 1378, 1642, 1657, 1659, 3727, 3755, 4187, 4368, 4413, 4677, 4684, 4721, 4927, 4945, 5221, 5270, 5313, 5409, 5627, 5945, 7587, 7588, 7789

Offset: 1

Author

Vladimir Shevelev, Mar 06 2010

Keywords

• nonn

Examples

			1 is in the sequence because A046132(1)=7 and A006512(1)=5 are twin primes.
		

Crossrefs

Cf. A006512, A046132.

Programs

Maple

A023200 := proc(n) option remember; if n = 1 then 3; else p := nextprime(procname(n-1)) ; while not isprime(p+4) do p := nextprime(p) ; end do: p ; end if; end proc:
A046132 := proc(n) 4+A023200(n) ; end proc:
A001359 := proc(n) option remember; if n = 1 then 3; else p := nextprime(procname(n-1)) ; while not isprime(p+2) do p := nextprime(p) ; end do: p ; end if; end proc:
A006512 := proc(n) 2+A001359(n) ; end proc:
for n from 1 do if A046132(n)+2 = A006512(n) or A046132(n) = A006512(n)+2 then printf("%d,\n",n); end if; end do: # R. J. Mathar, Nov 03 2011

Extensions

Extended beyond 28 by R. J. Mathar, Nov 03 2011

More terms from Michel Marcus, Dec 19 2018