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.

A326630 Sum of the eighth largest parts in the partitions of n into 10 squarefree parts.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 4, 5, 8, 9, 14, 18, 26, 30, 41, 50, 66, 77, 100, 117, 152, 174, 219, 252, 314, 357, 436, 499, 605, 685, 820, 929, 1109, 1243, 1469, 1650, 1947, 2169, 2536, 2833, 3297, 3663, 4235, 4707, 5424, 6000, 6867, 7604, 8684
Offset: 0

Views

Author

Wesley Ivan Hurt, Jul 14 2019

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Select[IntegerPartitions[n,{10}],AllTrue[#,SquareFreeQ]&][[All,8]]//Total,{n,0,60}] (* Harvey P. Dale, Apr 19 2020 *)

Formula

a(n) = Sum_{r=1..floor(n/10)} Sum_{q=r..floor((n-r)/9)} Sum_{p=q..floor((n-q-r)/8)} Sum_{o=p..floor((n-p-q-r)/7)} Sum_{m=o..floor((n-o-p-q-r)/6)} Sum_{l=m..floor((n-m-o-p-q-r)/5)} Sum_{k=l..floor((n-l-m-o-p-q-r)/4)} Sum_{j=k..floor((n-k-l-m-o-p-q-r)/3)} Sum_{i=j..floor((n-j-k-l-m-o-p-q-r)/2)} mu(r)^2 * mu(q)^2 * mu(p)^2 * mu(o)^2 * mu(m)^2 * mu(l)^2 * mu(k)^2 * mu(j)^2 * mu(i)^2 * mu(n-i-j-k-l-m-o-p-q-r)^2 * p, where mu is the Möbius function (A008683).
a(n) = A326627(n) - A326628(n) - A326629(n) - A326631(n) - A326632(n) - A326633(n) - A326634(n) - A326635(n) - A326636(n) - A326637(n).