A193687 Numbers n such that the sum of n-th average of a twin prime pair and the n-th twin prime is also a twin prime.

1, 2, 3, 4, 5, 6, 8, 10, 11, 13, 15, 22, 24, 32, 35, 36, 43, 44, 53, 55, 59, 67, 68, 70, 71, 73, 78, 82, 86, 108, 109, 113, 129, 132, 147, 151, 152, 154, 155, 159, 164, 165, 166, 168, 172, 173, 181, 193, 206, 211, 229, 231, 241, 260, 262, 271, 272, 277, 286

Offset

1,2

Links

Table of n, a(n) for n=1..59.

Example

a(8)=10 because 108+41=149 where 149 is a twin primes and A014574(10)=108, A001097(10)=41.

Maple

isA001097 := proc(n)
    if isprime(n) then
        if isprime(n+2) or isprime(n-2) then
            true;
        else
            false;
        end if;
    else
        false;
    end if;
end proc:
# see A001097 and A014574 for the other pieces of the Maple program
for n from 1 to 300 do
    if isA001097(A001097(n)+A014574(n)) then
        printf("%d, ", n);
    end if;
end do: # R. J. Mathar, Feb 19 2015

Crossrefs

Cf. A001097, A014574.

Sequence in context: A260317 A072666 A075471 * A000933 A253012 A036409

Adjacent sequences: A193684 A193685 A193686 * A193688 A193689 A193690

Keyword

nonn

Author

Juri-Stepan Gerasimov, Dec 18 2011

Extensions

Corrected by R. J. Mathar, Feb 19 2015

Status

approved