A156782 Primes : if sums of prime number and 4 consecutive prime numbers on-left-and-on-right are also primes.

19, 29, 43, 73, 137, 149, 157, 179, 211, 379, 383, 401, 409, 433, 467, 557, 569, 577, 599, 677, 839, 863, 883, 919, 997, 1103, 1303, 1499, 1553, 1637, 1669, 1709, 1783, 1811, 1861, 1873, 1951, 2113, 2207, 2309, 2393, 2503, 2647, 2663, 2713, 2791, 3011

Offset

1,1

Comments

7+11+13+17+19=67(prime);19+23+29+31+37=139(prime),... prime(n)+prime(n-1)+prime(n-2)+prime(n-3)+prime(n-4) are primes and prime(n)+prime(n+1)+prime(n+2)+prime(n+3)+prime(n+4) are also primes.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

lst={}; Do[p0=Prime[n+0]; p1=Prime[n+1]; p2=Prime[n+2]; p3=Prime[n+3]; p4=Prime[n+4]; p5=Prime[n+5]; p6=Prime[n+6]; p7=Prime[n+7]; p8=Prime[n+8]; If[PrimeQ[p0+p1+p2+p3+p4]&&PrimeQ[p4+p5+p6+p7+p8], AppendTo[lst, p4]], {n, 7!}]; lst
Transpose[Select[Partition[Prime[Range[500]], 9, 1], And@@PrimeQ[{Total[ Take[#, 5]], Total[Take[#, -5]]}]&]][[5]] (* Harvey P. Dale, Jul 11 2013 *)

Crossrefs

Cf. A156781

Sequence in context: A100590 A046120 A063644 * A347366 A092600 A106124

Adjacent sequences: A156779 A156780 A156781 * A156783 A156784 A156785

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Feb 15 2009

Status

approved