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A092446 Numbers n such that if P = 10*n^2+1, then P, P+6, P+12 and P+18 are all primes. 0
1, 2, 5, 8, 20, 83, 110, 128, 141, 216, 223, 334, 506, 810, 825, 867, 1086, 1171, 1861, 2178, 2295, 2680, 2911, 3803, 4884, 7737, 8010, 8457, 8520, 9858, 9882, 10379, 11871 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..33.

EXAMPLE

a(3) = 5; 10*5^2+1 = 251. 251+6 = 257; 251+12 = 263; 251+18=269. 251, 257, 263 and 269 are all primes.

MATHEMATICA

pQ[n_]:=Module[{x=10n^2+1}, And@@PrimeQ/@(x+ {0, 6, 12, 18})]; Select[Range[12000], pQ]  (* Harvey P. Dale, Mar 22 2011 *)

CROSSREFS

Sequence in context: A139407 A107384 A205596 * A087077 A200276 A168081

Adjacent sequences:  A092443 A092444 A092445 * A092447 A092448 A092449

KEYWORD

nonn

AUTHOR

Ray G. Opao, Mar 24 2004

EXTENSIONS

More terms from Harvey P. Dale, Mar 22 2011.

STATUS

approved

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Last modified February 24 01:16 EST 2020. Contains 332195 sequences. (Running on oeis4.)