OFFSET
1,2
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
EXAMPLE
1 is present as prime(2)-prime(1) = 3-2 = 1 = 1 mod 3.
4 is present as prime(5)-prime(4) = 11-7 = 4 = 1 mod 3.
MATHEMATICA
Select[Range@ 222, Mod[Prime[# + 1] - Prime@ #, 3] == 1 &] (* Michael De Vlieger, Mar 17 2016 *)
PROG
(Scheme, with Antti Karttunen's IntSeq-library)
(PARI) isok(n) = ((prime(n+1) - prime(n)) % 3) == 1; \\ Michel Marcus, Mar 17 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Mar 16 2016
STATUS
approved