A103824 Choose a(n) to be the smallest number not yet used such that: a(1) = 1, a(2n) = prime, a(2n+1) = composite and partial sums are alternately composite or prime.

1, 3, 9, 2, 4, 5, 35, 7, 65, 11, 15, 13, 21, 17, 25, 19, 55, 23, 49, 29, 91, 31, 27, 37, 115, 41, 77, 43, 121, 47, 85, 53, 125, 59, 39, 61, 33, 67, 133, 71, 143, 73, 119, 79, 95, 83, 81, 89, 145, 97, 51, 101, 99, 103, 45, 107, 57, 109, 87, 113, 69, 127, 75, 131, 111, 137

Offset

1,2

Links

Table of n, a(n) for n=1..66.

Crossrefs

Cf. A075593, A075594, A103825.

Sequence in context: A275371 A225357 A201664 * A155080 A010780 A309275

Adjacent sequences: A103821 A103822 A103823 * A103825 A103826 A103827

Keyword

nonn

Author

Ray Chandler Feb 16 2005

Extensions

Definition corrected by Zak Seidov, Feb 20 2005

Status

approved