A241686 a(1)=1, a(2)=2, a(3)=3; for n>=4, a(n) = n - A082467(n).

1, 2, 3, 3, 3, 5, 3, 5, 7, 7, 5, 11, 7, 11, 13, 13, 11, 17, 7, 17, 19, 13, 17, 19, 19, 23, 23, 19, 17, 29, 19, 23, 29, 31, 29, 31, 31, 29, 37, 37, 29, 41, 19, 41, 43, 31, 41, 43, 37, 47, 43, 43, 47, 47, 43, 53, 53, 43, 47, 59, 43, 53, 59, 61, 59, 61, 61, 53

Offset

1,2

Comments

a(i)=i, i=1,2,3, since A082467 is natural extended as 0 for n=1,2,3. For n>=2, a(n) and 2*n-a(n) are both primes. Sequence {2*n - a(n)} begins 1,2,3,5,7,7,11,11,11,13,17,13,19,17,17,19,23,19,31,...

Links

Peter J. C. Moses, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A082467.

Sequence in context: A057957 A359507 A366660 * A076559 A102601 A092308

Adjacent sequences: A241683 A241684 A241685 * A241687 A241688 A241689

Keyword

nonn

Author

Vladimir Shevelev, Apr 27 2014

Extensions

More terms from Peter J. C. Moses

Status

approved