Sequence to think about

[Robert G. Wilson v]

%I A000001
%S A000001
1,2,2,1,2,1,5,1,1,2,1,1,2,1,1,1,2,1,1,3,1,1,1,1,1,2,1,2,1,1,1,1,3,1,2,
%T A000001
1,1,1,1,1,2,1,2,1,4,1,1,1,5,1,1,2,1,1,1,1,5,1,1,2,1,1,1,2,1,1,1,1,3,1,
%U A000001
1,1,1,1,1,1,1,1,1,1,2,1,2,1,1,1,1,1,3,1,1,1,1,1,1,1,1,3,1,1,1,1,1,5,1
%N A000001 Least k such that nextprime(k*p(n)) - k*p(n) is composite.
%t A000001 NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k];
f[n_] := Block[{k = 1},
   While[ PrimeQ[ NextPrim[k*Prime[n]] - k*Prime[n]], k++ ]; k]; Table[
f[n], {n, 1, 105}]
%O A000001 1,2
%K A000001 ,nonn,
%A A000001 David W. Wilson (davidwwilson at attbi.com) and Robert G. Wilson v
(rgwv at kspaint.com), May 31 2002


David Wilson wrote:

> %N A000000 Least k such that nextprime(k p(n)#) - k p(n)# is composite.