OFFSET
1,2
COMMENTS
a(n) = length of n-th row in A256015; A066028(n) = A256015(n,a(n)). - Reinhard Zumkeller, Jun 01 2015
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..500
MATHEMATICA
(* This program is not suitable to compute a large number of terms. *)
a[n_] := a[n] = Select[Total /@ Subsets[Table[Prime[i], {i, 1, n}]], PrimeQ] // Union // Length;
Table[Print[n, " ", a[n]]; a[n], {n, 1, 25}] (* Jean-François Alcover, Mar 12 2019 *)
PROG
(Haskell)
import Data.List (subsequences, nub)
a108018 = sum . map a010051' . nub . map sum .
tail . subsequences . flip take a000040_list
-- Reinhard Zumkeller, Dec 16 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Max Alekseyev, Sep 08 2006
EXTENSIONS
More terms from Alois P. Heinz, Oct 24 2015
STATUS
approved