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A179012
Primes that are the sum of three consecutive composite odd numbers.
1
61, 73, 107, 163, 197, 233, 263, 271, 331, 397, 409, 419, 467, 523, 571, 599, 677, 691, 757, 827, 839, 883, 929, 997, 1039, 1051, 1063, 1097, 1123, 1153, 1163, 1171, 1187, 1223, 1231, 1291, 1301, 1367, 1433, 1493, 1523, 1531, 1571, 1619, 1627, 1637, 1667, 1693, 1783
OFFSET
1,1
LINKS
EXAMPLE
15+21+25=61, 21+25+27=73, 33+35+39=107.
MATHEMATICA
lst={}; Do[If[!PrimeQ[n], s=n; k=1, Continue[]]; If[!PrimeQ[n+2], s+=n+2; k=2; q=2, If[!PrimeQ[n+4], s+=n+4; k=2; q=4, If[!PrimeQ[n+6], s+=n+6; k=2; q=6]]]; If[!PrimeQ[n+q+2], s+=n+q+2; k=3; q+=2, If[!PrimeQ[n+q+4], s+=n+q+4; k=3; q+=4, If[!PrimeQ[n+q+6], s+=n+q+6; k=3; q+=6]]]; If[PrimeQ[s], AppendTo[lst, s]], {n, 9, 6!, 2}]; lst
nn=1001; With[{compodd=Complement[Range[9, nn, 2], Prime[Range[ PrimePi[ nn]]]]}, Select[ Total/@ Partition[compodd, 3, 1], PrimeQ]] (* Harvey P. Dale, Dec 09 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved