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A332042 Number of integers whose Dedekind psi function (A001615) values are n. 2
1, 0, 1, 1, 0, 2, 0, 1, 0, 0, 0, 4, 0, 1, 0, 0, 0, 2, 0, 1, 0, 0, 0, 5, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 4, 0, 1, 0, 0, 0, 2, 0, 1, 0, 0, 0, 6, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 2, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 9, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

EXAMPLE

a(6) = 2 since there are 2 solutions to psi(x) = 6: 4 and 5.

MATHEMATICA

psi[1] = 1; psi[n_] := n * Times @@ (1 + 1/Transpose[FactorInteger[n]][[1]]); m = 100; v = Table[0, {m}]; Do[i = psi[k]; If[i <= m, v[[i]]++], {k, 1, m}]; v

CROSSREFS

Cf. A001615, A054973, A063974, A332036, A332038, A332040.

Sequence in context: A124304 A165408 A186733 * A171368 A322353 A133988

Adjacent sequences:  A332039 A332040 A332041 * A332043 A332044 A332045

KEYWORD

nonn

AUTHOR

Amiram Eldar, Feb 05 2020

STATUS

approved

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Last modified July 25 09:49 EDT 2021. Contains 346289 sequences. (Running on oeis4.)