A075593 a(1) = 1, a(2n) = prime, a(2n+1) = composite and sum of two successive terms is alternately composite or prime.

1, 3, 4, 2, 9, 5, 6, 19, 10, 11, 8, 7, 12, 13, 16, 17, 14, 31, 22, 23, 18, 37, 24, 41, 20, 29, 30, 47, 26, 43, 28, 53, 36, 59, 38, 61, 40, 71, 32, 67, 34, 83, 44, 73, 54, 79, 48, 97, 42, 101, 50, 103, 46, 89, 60, 109, 58, 107, 56, 113, 66, 137, 62, 127, 52, 131, 68, 139, 72

Offset

1,2

Comments

This is not a permutation of the positive integers; odd composites > 9 will not appear in the sequence. - Klaus Brockhaus, Feb 06 2006

Links

Table of n, a(n) for n=1..69.

Crossrefs

Cf. A075594, A103824, A103825.

Sequence in context: A199271 A215175 A091477 * A145421 A338245 A352417

Adjacent sequences: A075590 A075591 A075592 * A075594 A075595 A075596

Keyword

nonn

Author

Amarnath Murthy, Sep 27 2002

Extensions

Extended by Ray Chandler Feb 16 2005

Status

approved