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A346377 a(n) is the number of solutions k to A075254(k) = n. 2
1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 2, 1, 0, 1, 0, 1, 0, 0, 1, 2, 1, 0, 2, 0, 0, 1, 0, 1, 0, 1, 1, 2, 1, 0, 1, 1, 1, 1, 1, 0, 0, 0, 2, 2, 0, 0, 0, 1, 0, 1, 1, 1, 1, 0, 1, 3, 0, 0, 2, 1, 0, 1, 0, 0, 0, 2, 0, 3, 1, 0, 1, 0, 2, 0, 0, 1, 0, 0, 2, 1, 2, 0, 1, 0, 1, 2, 0, 0, 0, 2, 1, 3, 1, 0, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,14
COMMENTS
a(n) is the number of k such that k + A001414(k) = n.
LINKS
EXAMPLE
a(14) = 2 because there are two solutions to A075254(k) = 14, namely
A075254(7) = 7+7 = 14
A075254(8) = 8+2+2+2 = 14
MAPLE
f:= proc(n) local t; add(t[1]*t[2], t=ifactors(n)[2])+n end proc:
N:= 100: # for a(1)..a(N)
V:= Vector(N):
for n from 1 to N do
v:= f(n);
if v <= N then V[v]:= V[v]+1 fi
od:
convert(V[1..N], list);
MATHEMATICA
f[1] = 1; f[n_] := n + Plus @@ Times @@@ FactorInteger[n]; m = 100; v = Table[0, {m}]; Do[i = f[n]; If[i <= m, v[[i]]++], {n, 1, m}]; v (* Amiram Eldar, Jul 14 2021 *)
CROSSREFS
Sequence in context: A144961 A144627 A135929 * A338757 A080733 A080732
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Jul 14 2021
STATUS
approved

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Last modified April 25 03:15 EDT 2024. Contains 371964 sequences. (Running on oeis4.)