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.

Showing 1-3 of 3 results.

A145073 Coefficient of x^(3^n) in Q(x)^(n+1), where Q(x) = Sum_{k>=0} (x^(3^k) + x^(2*3^k)).

Original entry on oeis.org

1, 2, 7, 44, 325, 3110, 34258, 436304, 6246439, 99637730, 1747851787, 33469239848, 694321125511, 15513919320368, 371408549270425, 9484764686963792, 257355204923817028, 7393783957451330630, 224224270472995407877
Offset: 0

Views

Author

Paul D. Hanna, Oct 09 2008

Keywords

Crossrefs

Programs

  • PARI
    { a(n) = local( Q = sum(j=0,n,x^(3^j)+x^(2*3^j)) + O(x^(3^n+1)) ); polcoeff(Q^(n+1),3^n) }

Extensions

a(10)-a(12) from Alois P. Heinz, Apr 28 2009
a(13)-a(18) from Max Alekseyev, Dec 18 2011

A145074 Coefficient of x^(4^n) in Q(x)^(n+1) where Q(x) = Sum_{k>=0} (x^(4^k) + x^(2*4^k) + x^(3*4^k)).

Original entry on oeis.org

1, 3, 12, 97, 885, 10386, 141295, 2218987, 39171564, 770029605, 16652860169, 393052609026, 10051000032099, 276818387211471, 8168772682637220, 257133140827399753
Offset: 0

Views

Author

Paul D. Hanna, Oct 09 2008

Keywords

Crossrefs

Programs

  • PARI
    {a(n,q=4)=local(Q=sum(j=0,n,(x^(q^j)-x^(q*q^j))/(1-x^(q^j)+O(x^(q^n+1)))));polcoeff(Q^(n+1),q^n)}

Extensions

a(8)-a(10) from Sean A. Irvine, Mar 31 2011
a(11)-a(15) from Max Alekseyev, Dec 19 2011

A145075 Coefficient of x^(5^n) in Q(x)^(n+1), where Q(x) = Sum_{k>=0} (x^(5^k) + x^(2*5^k) + x^(3*5^k) + x^(4*5^k)).

Original entry on oeis.org

1, 4, 18, 172, 1881, 25644, 411488, 7581792, 157296141, 3630709734, 92225760033, 2556393882912, 76774488792326, 2483261807354874
Offset: 0

Views

Author

Paul D. Hanna, Oct 09 2008

Keywords

Crossrefs

Programs

  • PARI
    {a(n,q=5)=local(Q=sum(j=0,n,(x^(q^j)-x^(q*q^j))/(1-x^(q^j)+O(x^(q^n+1)))));polcoeff(Q^(n+1),q^n)}

Extensions

a(7)-a(13) from Max Alekseyev, Dec 19 2011
Showing 1-3 of 3 results.