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A286478
Ordinal transform of A034968, factorial base digit sum.
4
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
0,3
FORMULA
For all n>= 1, a(A000142(n)) = n.
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 *)
CROSSREFS
Cf. A000142, A034968, A254524 (base-10 analog).
Sequence in context: A029334 A375825 A275078 * A340756 A030273 A029197
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, May 20 2017
STATUS
approved