OFFSET
1,2
EXAMPLE
a(1) = 2 - 1 = 1,
a(2) = 23 - 2 = 21,
a(3) = 37 - 3 = 34.
MAPLE
A007510 := proc(n) option remember; if n <= 2 then op(n, [2, 23]) ; else for a from procname(n-1)+2 by 2 do if isprime(a) and not isprime(a+2) and not isprime(a-2) then return a; end if; end do: end if; end proc:
seq(A167397(n), n=1..120) ; # R. J. Mathar, May 30 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Nov 02 2009, Nov 05 2009
EXTENSIONS
Corrected (220 replaced with 230, 225 with 235) by R. J. Mathar, May 30 2010
STATUS
approved