OFFSET
0,1
COMMENTS
Is there any n for which a(n) = -1?
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..1292
FORMULA
A362181(a(n)) = n.
MATHEMATICA
ucototient[n_] := n - Times @@ (Power @@@ FactorInteger[n] - 1); ucototient[1] = 0; With[{max = 300}, solnum = Table[0, {n, 1, max}]; Do[If[(i = ucototient[k]) <= max, solnum[[i]]++], {k, 2, max^2}]; Join[{2, 0}, TakeWhile[FirstPosition[ solnum, #] & /@ Range[2, max] // Flatten, NumberQ]]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Apr 10 2023
STATUS
approved