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A060332
Primes the sum of seven consecutive composite numbers.
4
173, 359, 367, 383, 457, 541, 593, 619, 643, 659, 811, 877, 929, 1087, 1103, 1129, 1181, 1223, 1481, 1489, 1549, 1753, 1787, 1811, 2039, 2063, 2129, 2137, 2239, 2297, 2347, 2371, 2549, 2557, 2693, 2711, 2719, 2767, 2819, 2843, 2851, 3061, 3163, 3187
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 ] + composite[ n + 4 ] + composite[ n + 5 ] + composite[ n + 6 ]; If[ PrimeQ[ p ], a = Append[ a, p ] ], {n, 1, 2000} ]; a
Module[{upto=500, cmps}, cmps=Select[Range[upto], CompositeQ]; Select[ Total/@ Partition[ cmps, 7, 1], PrimeQ]] (* Harvey P. Dale, Oct 24 2021 *)
CROSSREFS
Sequence in context: A142004 A047986 A096703 * A142022 A130338 A275968
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Mar 30 2001
STATUS
approved