The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A212658 Number of multisets {1^k1, 2^k2, ..., n^kn}, ki >= 0, with the sum of reciprocals <= 1. 2
 1, 2, 4, 8, 17, 37, 86, 199, 475, 1138, 2769, 6748, 16613, 40904, 101317, 251401, 624958, 1555940, 3882708, 9701790, 24276866, 60817940, 152508653, 382828565, 961859364, 2418662434, 6086480305, 15327208770, 38622901484, 97384378728, 245686368946, 620158662562 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The number of distinct sums of reciprocals is given by A212606. LINKS Dexter Senft, Table of n, a(n) for n = 0..36 PROG (C#) /* For n=43 or greater, the least common multiple of the numbers 1..n requires more than 64 bits to represent, and C# has no such native data type. */ using System; using System.Collections.Generic; namespace A212658 {    class Program {       static long Result;       static long GCD(long n, long m) {          long mod;          long j = n numbers = new List();          for (int n=1; n<=42; n++) {             long lcm= LCM(n);             numbers.Clear();             Result = 0;             for (int i=2; i<=n; i++) numbers.Add(lcm/i);             Count(lcm, numbers, 0);             Console.Write(n.ToString() + ": " + (Result+2).ToString() + "\n");          }       }       static void Count(long Target, List L, int At) {          if (At >= L.Count) return;          if (L[At] <= Target) {             Result++;             long AmtLeft = Target - L[At];             if (AmtLeft >= L[L.Count-1]) Count(AmtLeft, L, At);          }          Count(Target, L, At+1);          return;       }    } } /* Dexter Senft, Feb 07 2019 */ CROSSREFS Cf. A212657, A212606, A212607, A020473, A092669, A092671, A208480, A003418. Sequence in context: A003426 A179476 A087803 * A036374 A214999 A084635 Adjacent sequences:  A212655 A212656 A212657 * A212659 A212660 A212661 KEYWORD nonn AUTHOR Max Alekseyev, May 23 2012 EXTENSIONS a(24)-a(25) from Alois P. Heinz, Nov 20 2017 a(26)-a(31) from Dexter Senft, Feb 07 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 22 16:29 EST 2020. Contains 331152 sequences. (Running on oeis4.)