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A213021
Least k such that k*30^n+1 is prime
1
1, 2, 2, 2, 2, 3, 7, 9, 2, 19, 13, 21, 25, 10, 22, 60, 2, 5, 11, 25, 9, 41, 11, 14, 53, 21, 141, 54, 137, 79, 30, 1, 2, 51, 16, 5, 8, 9, 39, 5, 10, 74, 11, 3, 61, 25, 69, 32, 104, 129, 44, 48, 151, 243, 19, 165, 7, 96, 20, 93, 130, 136, 98, 25, 102, 156, 74
OFFSET
1,2
MATHEMATICA
Table[k = 1; While[! PrimeQ[k*30^n + 1], k++]; k, {n, 100}] (* T. D. Noe, Jun 06 2012 *)
PROG
PFGW64 and SCRIPTIFY from Primeform Group
Command : pfgw64 -f in.txt
in.txt file :
SCRIPT
DIM nn, 0
DIM kk
DIMS tt
OPENFILEOUT myfile, a(n).txt
LABEL loopn
SET nn, nn+1
IF nn>2000 THEN END
SET kk, 0
LABEL loopk
SET kk, kk+1
SETS tt, %d, %d\,; nn; kk
PRP kk*30^nn+1, tt
IF ISPRP THEN GOTO b
IF ISPRIME THEN GOTO b
GOTO loopk
LABEL b
WRITE myfile, tt
GOTO loopn
(PARI)
a(n)=for(k=1, 10^10, if(isprime(k*30^n+1), return(k)));
vector(66, n, a(n))
/* Joerg Arndt, Jun 03 2012 */
CROSSREFS
Sequence in context: A333528 A319187 A248780 * A078228 A119762 A153667
KEYWORD
nonn
AUTHOR
Pierre CAMI, Jun 03 2012
STATUS
approved