

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.


0



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
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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



EXAMPLE

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


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS

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


STATUS

approved



