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A060329
Primes the sum of four consecutive composite numbers.
6
97, 193, 263, 311, 337, 383, 457, 503, 647, 673, 839, 887, 937, 1009, 1033, 1103, 1223, 1319, 1487, 1511, 1583, 1609, 1777, 1801, 1823, 1873, 2017, 2377, 2423, 2447, 2593, 2617, 2687, 2713, 2903, 2927, 2999, 3023, 3049, 3361, 3407, 3457, 3623, 3671
OFFSET
1,1
LINKS
MATHEMATICA
composite[ n_Integer ] := (k = n + PrimePi[ n ] + 1; While[ k - PrimePi[ k ] - 1 != n, k++ ]; k); a = {}; Do[ p = composite[ n ] + composite[ n + 1 ] + composite[ n + 2 ] + composite[ n + 3 ]; If[ PrimeQ[ p ], a = Append[ a, p ] ], {n, 1, 1000} ]; a
nn=1000; With[{comps=Complement[Range[2, nn], Prime[Range[PrimePi[ nn]]]]}, Select[ Total/@Partition[comps, 4, 1], PrimeQ]] (* Harvey P. Dale, Jan 02 2013 *)
CROSSREFS
Sequence in context: A364321 A142398 A133870 * A157924 A323796 A044429
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Mar 30 2001
STATUS
approved