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A104369 Number of divisors of A104350(n) + 1. 3
2, 2, 2, 2, 2, 2, 4, 2, 2, 4, 2, 2, 4, 4, 4, 16, 16, 4, 2, 16, 4, 4, 8, 4, 2, 16, 8, 8, 2, 8, 16, 32, 16, 32, 16, 8, 8, 16, 128, 4, 32, 16, 16, 4, 16, 8, 16, 4, 8, 128, 16, 4, 16, 4, 8, 4, 16, 8, 16, 32, 8, 16, 16, 4, 2, 4, 16, 64, 16, 8, 8, 16, 16, 64, 64, 64 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..76.

Reinhard Zumkeller, Products of largest prime factors of numbers <= n

FORMULA

a(n) = A000005(A104365(n)).

MATHEMATICA

a[n_] := DivisorSigma[0, 1 + Product[FactorInteger[k][[-1, 1]], {k, 1, n}]]; Array[a, 76] (* Amiram Eldar, Feb 12 2020 *)

CROSSREFS

Cf. A000005, A064144, A104361, A104365, A104370.

Sequence in context: A003648 A003642 A100007 * A051702 A073130 A238267

Adjacent sequences:  A104366 A104367 A104368 * A104370 A104371 A104372

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 06 2005

EXTENSIONS

a(51)-a(76) from Amiram Eldar, Feb 12 2020

STATUS

approved

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Last modified January 22 21:47 EST 2022. Contains 350504 sequences. (Running on oeis4.)