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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 January 19 14:53 EST 2020. Contains 331049 sequences. (Running on oeis4.)