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A187088 Least odd k such that k*2^(2^n)+1 is prime. 1
1, 1, 1, 1, 1, 43, 25, 21, 207, 223, 1125, 2577, 3091, 9165, 6223, 3493, 1063 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

LINKS

Table of n, a(n) for n=0..16.

Mark Rodenkirch: OpenPFGW (for running the PFGW the program).

MATHEMATICA

Table[k=1; While[! PrimeQ[k*2^2^n + 1], k=k+2]; k, {n, 0, 10}]

PROG

(PFGW)

SCRIPT

DIM nn, -1

DIM kk

DIMS tt

LABEL loopn

SET nn, nn+1

SET kk, -1

LABEL loopk

SET kk, kk+2

SETS tt, %d, %d\,; nn; kk

PRP kk*2^(2^nn)+1, tt

IF ISPRP THEN GOTO loopn

GOTO loopk

\PFGW -t FILE.txt

FILE.txt =

ABC $a

43*2^(2^5)+1

25*2^(2^6)+1

21*2^(2^7)+1

207*2^(2^8)+1

223*2^(2^9)+1

1125*2^(2^10)+1

2577*2^(2^11)+1

3091*2^(2^12)+1

9165*2^(2^13)+1

6223*2^(2^14)+1

3493*2^(2^15)+1

1063*2^(2^16)+1

CROSSREFS

Sequence in context: A097398 A225210 A033363 * A127147 A298078 A291494

Adjacent sequences:  A187085 A187086 A187087 * A187089 A187090 A187091

KEYWORD

nonn

AUTHOR

Pierre CAMI, Mar 08 2011

STATUS

approved

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Last modified July 25 07:08 EDT 2021. Contains 346284 sequences. (Running on oeis4.)