A104370 Sum of divisors of A104365(n) = A104350(n) + 1.

3, 4, 8, 14, 62, 182, 1372, 2522, 7562, 38272, 415802, 1247402, 16313472, 114107904, 570257104, 1161216000, 21043021824, 57893308852, 1099944846002, 5530978026000, 39437046917604, 425165932107504, 10235889009520064, 29233062045242352, 146100174169950002, 1917846796927501440, 5805987050510562240, 39918123659008838880

Offset

1,1

Links

Max Alekseyev, Table of n, a(n) for n = 1..158 (terms 1..76 terms from Amiram Eldar, terms 142..151 from Tyler Busby)

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

Formula

a(n) = A000203(A104365(n)).

Mathematica

a[n_] := DivisorSigma[1, 1 + Product[FactorInteger[k][[-1, 1]], {k, 1, n}]]; Array[a, 30] (* Amiram Eldar, Feb 12 2020 *)

Crossrefs

Cf. A000203, A104350, A104362, A104365, A104366, A104367, A104368, A104369, A104371, A104372.

Sequence in context: A026632 A332985 A026654 * A310013 A033854 A042981

Adjacent sequences: A104367 A104368 A104369 * A104371 A104372 A104373

Keyword

nonn

Author

Reinhard Zumkeller, Mar 06 2005

Status

approved