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A223935 Odd primes p(i) such that 6*p(i+j)^2-1 is also prime for j = 0..3. 1
48497, 48907, 493747, 578453, 1223777, 1249363, 1933363, 3304607, 5160217, 5765083, 6022087, 6205937, 7740127, 7757447, 7862843, 8173537, 8938627, 11989177, 13789033, 17649223, 18142693, 18829117, 20006813, 20601593, 23938867, 24448063, 24478043 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Pierre CAMI, Table of n, a(n) for n = 1..131

EXAMPLE

p(4990)=48497 and 6*48497*48497-1=14111754053 is prime,

p(4991)=48523 and 6*48523*48523-1=14126889173 is prime,

p(4992)=48527 and 6*48527*48527-1=14129218373 is prime,

p(4993)=48533 and 6*48533*48533-1=14132712533 is prime,

so a(1)=p(4990)=48497

MATHEMATICA

Reap[ For[ n=1; i=2, i < 5*10^6, i++, If[And @@ PrimeQ /@ Table[p[j] = Prime[i+j]; 6*p[j]^2-1, {j, 0, 3}], Print["i = ", i, " a(", n, ") = ", p[0]]; n++; Sow[ p[0] ] ] ] ][[2, 1]] (* Jean-Fran├žois Alcover, Apr 09 2013 *)

PROG

PFGW and SCRIPTIFY

SCRIPT

DIM i, 4000

DIMS t

OPENFILEOUT myf, res.txt

LABEL loop1

SET i, i+1

IF i==9999997 THEN END

SETS t, %d, %d\,; i; p(i)

PRP 6*p(i)*p(i)-1, t

IF  ISPRP THEN GOTO a

GOTO loop1

LABEL a

SET i, i+1

SETS t, %d, %d\,; i; p(i)

PRP 6*p(i)*p(i)-1, t

IF  ISPRP THEN GOTO b

GOTO loop1

LABEL b

SET i, i+1

SETS t, %d, %d\,; i; p(i)

PRP 6*p(i)*p(i)-1, t

IF  ISPRP THEN GOTO c

GOTO loop1

LABEL c

SET i, i+1

SETS t, %d, %d\,; i; p(i)

PRP 6*p(i)*p(i)-1, t

IF  ISPRP THEN WRITE myf, t

GOTO loop1

CROSSREFS

Sequence in context: A151876 A083627 A031650 * A278020 A237105 A234230

Adjacent sequences:  A223932 A223933 A223934 * A223936 A223937 A223938

KEYWORD

nonn

AUTHOR

Pierre CAMI, Mar 29 2013

STATUS

approved

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Last modified September 17 04:03 EDT 2019. Contains 327119 sequences. (Running on oeis4.)