A242768 Indices of twin primes in {A242758(n)-3}.

1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 3, 3, 3, 6, 6, 6, 6, 6, 6, 2, 2, 5, 5, 5, 5, 5, 2, 2, 6, 6, 6, 6, 6, 6, 2, 2, 2, 2, 4, 4, 4, 4, 3, 3, 3, 5, 5, 5, 5, 5, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 2, 2, 6

Offset: 2

Author

Vladimir Shevelev, May 22 2014

Keywords

• nonn

Comments

For the definition of the index of a twin primes pair, see the comment in A242767.

The sequence is constructed as follows. Consider the sequence {A242758(n)-3}. It begins 3,5,11,11,17,17,29,29,29,...

These numbers occur in A001359 (lesser of twin primes) at the indices 1,2,3,3,4,4,5,5,5,...

We add 1: 2,3,4,4,5,5,6,6,6,... (since in A001359 n>=1, while in A242767 n>=2). Now A242767{2,3,4,4,5,5,6,6,6,...} = {1,1,2,2,2,2,3,3,3,...}: we obtain this sequence.

Links

• Peter J. C. Moses, Table of n, a(n) for n = 2..5001

Crossrefs

Cf. A001359, A006512, A242489, A242490, A242720, A242758, A242767.

Extensions

More terms from Peter J. C. Moses, May 23 2014