OFFSET
1,3
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..1024 (First 500 terms from Reinhard Zumkeller)
MATHEMATICA
nn = 63; c[_] = 0; r = k = a[1] = c[1] = 1; Reap[Do[w = Union@ Array[a, k]; Do[Set[a[j + k], c[w[[j]]]], {j, Length[w]}]; Do[c[a[j + k]]++, {j, Length[w]}]; k += Sow[Length[w]], {nn}]][[-1, -1]] (* Michael De Vlieger, Nov 15 2022 *)
PROG
(Haskell)
a030719 n = a030719_list !! (n-1)
a030719_list = tail $ zipWith (-) (tail a253170_list) a253170_list
-- Reinhard Zumkeller, Dec 28 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved