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

1,2

Links

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

Example

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

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

Crossrefs

Cf. A006512, A046132.

Sequence in context: A309485 A228378 A326464 * A263261 A290275 A156787

Adjacent sequences: A174039 A174040 A174041 * A174043 A174044 A174045

Keyword

nonn

Author

Vladimir Shevelev, Mar 06 2010

Extensions

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

More terms from Michel Marcus, Dec 19 2018

Status

approved