A286478 Ordinal transform of A034968, factorial base digit sum.
1, 1, 2, 1, 2, 1, 3, 3, 4, 2, 3, 1, 5, 4, 5, 2, 3, 1, 6, 4, 5, 2, 3, 1, 4, 6, 7, 7, 8, 6, 8, 9, 10, 7, 8, 4, 11, 9, 10, 5, 6, 2, 11, 7, 8, 3, 4, 1, 9, 12, 13, 12, 13, 9, 14, 14, 15, 10, 11, 5, 16, 12, 13, 6, 7, 2, 14, 8, 9, 3, 4, 1, 15, 17, 18, 15, 16, 10, 19, 17, 18, 11, 12, 5, 19, 13, 14, 6, 7, 2, 15, 8, 9, 3, 4, 1, 20, 20, 21, 16, 17, 10, 22, 18, 19, 11, 12
Offset: 0
Links
Programs
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Mathematica
f[n_] := If[n == 0, 0, Module[{s = 0, i = 2, k = n}, While[k>0, k = Floor[n/i!]; s += (i-1) k; i++]; n-s]]; b[_] = 1; a[n_] := a[n] = With[{t = f[n]}, b[t]++]; a /@ Range[0, 100] (* Jean-François Alcover, Dec 19 2021 *)
Formula
For all n>= 1, a(A000142(n)) = n.