OFFSET
1,3
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = A031131(n) - 2 for n > 1. - Reinhard Zumkeller, Dec 19 2013
EXAMPLE
23 is in a sea of 8 composites: 20,21,22,23,24,25,26,27,28.
MAPLE
[ seq(ithprime(i)-ithprime(i-2)-2, i=3..100) ];
MATHEMATICA
Table[ Prime[n + 2] - Prime[n] - 2, {n, 75}] (* Robert G. Wilson v Oct 27 2004 *)
Join[{1}, #[[3]]-#[[1]]-2&/@Partition[Prime[Range[90]], 3, 1]] (* Harvey P. Dale, Sep 26 2012 *)
PROG
CROSSREFS
KEYWORD
nonn,easy,nice
AUTHOR
EXTENSIONS
More terms from Michel ten Voorde
STATUS
approved