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 A020696 Let a,b,c,...k be all divisors of n; a(n) = (a+1)*(b+1)*...*(k+1). 7
 2, 6, 8, 30, 12, 168, 16, 270, 80, 396, 24, 10920, 28, 720, 768, 4590, 36, 31920, 40, 41580, 1408, 1656, 48, 2457000, 312, 2268, 2240, 104400, 60, 5499648, 64, 151470, 3264, 3780, 3456, 76767600, 76, 4680, 4480, 15343020, 84, 19071360, 88 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(p) = 2(p+1), a(p^2) = 2(p+1)(p^2+1) for primes p. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA a(n) = Product(A027750(n,k) + 1: k = 1..A000005(n)). - Reinhard Zumkeller, Mar 28 2015 MATHEMATICA Table[Times @@ (Divisors[n] + 1), {n, 43}] (* Ivan Neretin, May 27 2015 *) PROG (PARI) a(n) = {d = divisors(n); return (prod(i=1, #d, d[i]+1)); } \\ Michel Marcus, Jun 12 2013 (Haskell) a020696 = product . map (+ 1) . a027750_row' -- Reinhard Zumkeller, Mar 28 2015 CROSSREFS Cf. A027750, A000005, A003959. Cf. A057643 (LCM instead of product). Cf. A299436 (exp). Sequence in context: A210737 A140539 A056188 * A328769 A290249 A321471 Adjacent sequences:  A020693 A020694 A020695 * A020697 A020698 A020699 KEYWORD nonn,easy AUTHOR Amarnath Murthy, Jun 01 2003 EXTENSIONS Edited by Don Reble, Jun 05 2003 STATUS approved

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Last modified September 26 04:44 EDT 2020. Contains 337346 sequences. (Running on oeis4.)