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A098929 Smallest k>0 such that (2^k)*A002110(n) + 1 is prime. 2
1, 1, 1, 1, 1, 2, 3, 11, 2, 4, 1, 2, 3, 15, 23, 6, 11, 1, 7, 6, 7, 10, 1, 9, 28, 1, 3, 7, 63, 1, 25, 29, 13, 3, 25, 12, 9, 18, 20, 15, 66, 3, 5, 39, 10, 37, 15, 14, 31, 6, 9, 27, 12, 7, 15, 12, 6, 11, 41, 35, 116, 15, 7, 28, 6, 9, 23, 28, 23, 2, 2, 9, 5, 17, 27, 56, 69, 132, 29, 1, 20, 17 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Pierre CAMI, Table of n, a(n) for n = 1..1029

MATHEMATICA

f[n_] := Block[{k = 1, p = Product[Prime[i], {i, n}]}, While[ !PrimeQ[2^k*p + 1], k++ ]; k]; Table[ f[n], {n, 82}]

PROG

(PFGW & SCRIPT)

Command pfgw64 -f in.txt

in.txt = SCRIPT file

SCRIPT

DIM n, 0

DIM i, 0

DIM pp

DIMS t

OPENFILEOUT myf, a(n).txt

LABEL loop1

SET n, n+1

SET i, 0

LABEL loop2

SET i, i+1

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

SET pp, (2^i)*p(n)#+1

PRP pp, t

IF ISPRP THEN GOTO a

GOTO loop2

LABEL a

WRITE myf, t

GOTO loop1

CROSSREFS

Cf. A002110, A097099.

Sequence in context: A002443 A111788 A238455 * A073098 A201267 A046641

Adjacent sequences:  A098926 A098927 A098928 * A098930 A098931 A098932

KEYWORD

nonn

AUTHOR

Pierre CAMI and Robert G. Wilson v, Sep 27 2004

STATUS

approved

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Last modified February 15 16:25 EST 2019. Contains 320136 sequences. (Running on oeis4.)