OFFSET
1,1
COMMENTS
Subtracting from a(1) twice n=1 gives 5-2=3, which is a prime number; subtracting from a(2) twice n=2 gives 11-4=7, which is a prime number; subtracting from a(3) twice n=3 gives 17-6=11, which is a prime number; subtracting from a(4) twice n=4 gives 31-8=23, which is a prime number; etc.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1000
MAPLE
b:= proc(n) option remember; global a; a(n); b(n) end: a:= proc(n) option remember; local m; global b; if n=1 then b(1):= 3; 5 else for m from a(n-1)+2 by 2 while not (isprime(m) and (b(n-1)<m-2*n) and isprime (m-2*n)) do od; b(n):= m-2*n; m fi end: seq (a(n), n=1..100); # Alois P. Heinz, Feb 05 2009
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Eric Angelini, Jan 29 2009
EXTENSIONS
Corrected definition and more terms from Alois P. Heinz, Feb 05 2009
STATUS
approved