OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
2*3*5=30 29 and 31 twin primes, 3 and 5 first odd twin primes so k(1)=2
12*5*7=420 419 and 421 twin primes, 5 and 7 second odd twin primes so k(2)=12
6*11*13=858 857 and 859 twin primes, 11 and 13 third odd twin primes k(3)=6
MATHEMATICA
Module[{tp=Times@@@Select[Partition[Prime[Range[500]], 2, 1] , #[[2]]-#[[1]] == 2&], len, k}, len=Length[tp]; Table[k=1; While[!And@@PrimeQ[k*tp[[n]]+{1, -1}], k++]; k, {n, len}]] (* Harvey P. Dale, Mar 04 2013 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Pierre CAMI, May 26 2005
STATUS
approved