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 A345160 a(n) = Product_{k=1..n} sigma_3(k). 3
 1, 9, 252, 18396, 2317896, 584109792, 200933768448, 117546254542080, 88982514688354560, 100906171656594071040, 134407020646583302625280, 274727950201616270566072320, 603852034543152562704226959360, 1869525898945600334132286666178560 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Partial products of A001158. LINKS Vaclav Kotesovec, Table of n, a(n) for n = 1..180 Ramanujan's Papers, Some formulas in the analytic theory of numbers, Messenger of Mathematics, XLV, 1916, 81-84, Formula (20). FORMULA Lim_{n->infinity} (a(n) / (n!)^3)^(1/n) = A345159. MATHEMATICA Table[Product[DivisorSigma[3, k], {k, 1, n}], {n, 1, 20}] FoldList[Times, DivisorSigma[3, Range[20]]] (* Harvey P. Dale, Sep 18 2023 *) PROG (PARI) a(n) = prod(k=1, n, sigma(k, 3)); \\ Michel Marcus, Jun 10 2021 CROSSREFS Cf. A001158, A066843, A066780, A247951, A345159. Sequence in context: A158621 A256019 A135484 * A178186 A348861 A212290 Adjacent sequences: A345157 A345158 A345159 * A345161 A345162 A345163 KEYWORD nonn AUTHOR Vaclav Kotesovec, Jun 10 2021 STATUS approved

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Last modified December 3 19:10 EST 2023. Contains 367540 sequences. (Running on oeis4.)