cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A100953 Number of partitions of n into relatively prime parts such that multiplicities of parts are also relatively prime.

Original entry on oeis.org

1, 1, 0, 1, 2, 5, 5, 13, 14, 25, 28, 54, 54, 99, 105, 160, 192, 295, 315, 488, 546, 760, 890, 1253, 1404, 1945, 2234, 2953, 3459, 4563, 5186, 6840, 7909, 10029, 11716, 14843, 17123, 21635, 25035, 30981, 36098, 44581, 51370, 63259, 73223, 88739, 103048, 124752
Offset: 0

Views

Author

Vladeta Jovovic, Jan 11 2005

Keywords

Crossrefs

Programs

  • Maple
    read transforms : a000837 := [] : b000837 := fopen("b000837.txt",READ) : bfil := readline(b000837) : while StringTools[WordCount](bfil) > 0 do b := sscanf( bfil,"%d %d") ; a000837 := [op(a000837),op(2,b)] ; bfil := readline(b000837) ; od: fclose(b000837) ; a000837 := subsop(1=NULL,a000837) : a := MOBIUS(a000837) : for n from 1 to 120 do printf("%d, ",op(n,a)) ; od: # R. J. Mathar, Mar 12 2008
    # second Maple program:
    with(numtheory): with(combinat):
    b:= proc(n) option remember; `if`(n=0, 1, add(
           mobius(n/d)*numbpart(d), d=divisors(n)))
        end:
    a:= proc(n) option remember; `if`(n=0, 1, add(
           mobius(n/d)*b(d), d=divisors(n)))
        end:
    seq(a(n), n=0..60);  # Alois P. Heinz, Dec 19 2017
  • Mathematica
    Table[Length[Select[IntegerPartitions[n],And[GCD@@#===1,GCD@@Length/@Split[#]===1]&]],{n,20}] (* Gus Wiseman, Dec 19 2017 *)
    b[n_] := b[n] = If[n==0, 1, Sum[
         MoebiusMu[n/d]*PartitionsP[d], {d, Divisors[n]}]];
    a[n_] := a[n] = If[n==0, 1, Sum[
         MoebiusMu[n/d]*b[d], {d, Divisors[n]}]];
    a /@ Range[0, 60] (* Jean-François Alcover, May 21 2021, after Alois P. Heinz *)

Formula

Moebius transform of A000837.

Extensions

More terms from David Wasserman and R. J. Mathar, Mar 04 2008
a(0)=1 prepended by Alois P. Heinz, Dec 19 2017