OFFSET
1,1
COMMENTS
0 <= a(n) <= 4; a(A066388(n)) = 4.
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
a(1) = #{2, 0+2=2, 1+2=3, 0+1+2=3} = 4;
a(2) = #{2, 3, 1+2=3, 2+3=5} = 4;
a(3) = #{2, 3, 2+3=5, 3+4=7} = 4;
a(4) = #{3, 5, 3+4=7} = 3;
a(5) = #{5, 5+6=11} = 2.
MATHEMATICA
Table[Length[Select[{-1+n, n, 1+n, -1+2 n, 2 n, 1+2 n, 3 n}, PrimeQ]], {n, 105}]
ssp[{a_, b_, c_}]:=Count[Subsets[{a, b, c}, 3], _?(PrimeQ[Total[#]]&)]; ssp/@ Partition[ Range[0, 110], 3, 1] (* Harvey P. Dale, Jan 29 2013 *)
PROG
(Haskell)
a117499 1 = sum $ map a010051 [1, 2, 0 + 1, 0 + 2, 1 + 2, 0 + 1 + 2]
a117499 n = sum $ map a010051 [n - 1, n, n + 1, 2 * n - 1, 2 * n + 1]
-- Reinhard Zumkeller, Jan 10 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Mar 23 2006
STATUS
approved