A075639 a(1) = 1 and then group the prime numbers so that the n-th group contains n numbers with a composite sum: (1), (2, 7), (3, 5, 13), (11, 17, 19, 23), (29, 31, 37, 41, 47), (43, 53, 59, 61, 67, 71), ...

1, 2, 7, 3, 5, 13, 11, 17, 19, 23, 29, 31, 37, 41, 47, 43, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277

Offset

1,2

Links

Table of n, a(n) for n=1..60.

Example

1; 2,7; 3,5,13; 11,17,19,23; 29,31,37,41,47; 43,53,59,61,67,71; ...

Crossrefs

Cf. A075640, A075641, A075642.

Sequence in context: A372131 A365768 A330883 * A082737 A334971 A104957

Adjacent sequences: A075636 A075637 A075638 * A075640 A075641 A075642

Keyword

nonn,tabl

Author

Amarnath Murthy, Sep 30 2002

Extensions

More terms from David Wasserman, Jan 22 2005

Status

approved