The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A097099 Smallest k>0 such that (2^k)*A002110(n) - 1 is prime. 2
 1, 1, 1, 1, 2, 6, 1, 1, 2, 3, 12, 1, 2, 22, 2, 4, 13, 12, 6, 1, 4, 1, 4, 9, 2, 9, 5, 6, 2, 1, 9, 17, 22, 7, 19, 73, 23, 12, 5, 27, 33, 64, 33, 5, 7, 41, 44, 35, 29, 3, 19, 6, 26, 5, 11, 9, 33, 34, 16, 63, 46, 8, 4, 24, 48, 32, 11, 29, 26, 6, 25, 17, 31, 6, 46, 33, 46, 17, 8, 61, 12, 23, 76 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 LINKS Pierre CAMI, Table of n, a(n) for n = 1..1042 MATHEMATICA f[n_] := Block[{k = 1, p = Product[Prime[i], {i, n}]}, While[ !PrimeQ[2^k*p - 1], k++ ]; k]; Table[ f[n], {n, 83}] (* Robert G. Wilson v, Sep 27 2004 *) kp[n_]:=Module[{k=1}, While[!PrimeQ[2^k n-1], k++]; k]; With[{prmrls=Rest[ FoldList[Times, 1, Prime[Range[90]]]]}, kp/@prmrls] (* Harvey P. Dale, Feb 01 2012 *) PROG (PFGW & SCRIPT) Command pfgw64 -f in.txt in.txt file = 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, A098929. Sequence in context: A244814 A090185 A059813 * A316622 A197111 A065529 Adjacent sequences:  A097096 A097097 A097098 * A097100 A097101 A097102 KEYWORD nonn AUTHOR Pierre CAMI, Sep 15 2004 EXTENSIONS More terms from Robert G. Wilson v, Sep 27 2004 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 12 00:34 EDT 2022. Contains 356067 sequences. (Running on oeis4.)