OFFSET
1,1
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
Michael De Vlieger, Plot a(s(j) + k - 1) at (j,k) for j = 1..512 and s = partial sums of A030719, showing a(m) = 2 in red and a(m) != 2 in light blue.
MATHEMATICA
nn = 30; m = 2; c[_] = 0; k = a[1] = c[1] = 1; Reap[Do[w = Union@ Array[a, k]; Do[Set[a[j + k], c[w[[j]]]]; If[a[j + k] == m, Sow[m]], {j, Length[w]}]; Do[c[a[j + k]]++, {j, Length[w]}]; k += Length[w], {n, nn}] ][[-1, -1]] (* Michael De Vlieger, Nov 19 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved