A073679 a(1) = 4, a(n+1) is the smallest composite number > a(n) such that all of the differences a(n+1)-a(n) are distinct primes.

4, 6, 9, 14, 21, 32, 45, 62, 81, 104, 133, 164, 201, 242, 285, 332, 385, 444, 505, 572, 645, 716, 795, 878, 975, 1064, 1165, 1268, 1375, 1484, 1611, 1724, 1855, 1992, 2149, 2288, 2439, 2588, 2751, 2918, 3091, 3270, 3451, 3642, 3835, 4032, 4255, 4454, 4665

Offset

0,1

Comments

For the first 20 terms the differences are the first 19 primes in that order (from 2 to 67). But a(20) + 71 = 572 + 71 is a prime, so a(21) = 572 + 73.

Links

Table of n, a(n) for n=0..48.

Example

a(18) = 444 = a(17) + 59 = 385 + 59. All the primes <59 have already been used.

Crossrefs

Sequence in context: A175587 A339114 A175709 * A257559 A118689 A364489

Adjacent sequences: A073676 A073677 A073678 * A073680 A073681 A073682

Keyword

nonn

Author

Amarnath Murthy, Aug 11 2002

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 24 2003

Status

approved