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.

A111468 Leading diagonal of A111467.

Original entry on oeis.org

1, 3, 14, 56, 280, 1872, 11760, 104832, 1224720, 12545280, 96526080, 1163289600, 13891046400, 200222668800, 2917119744000, 47259168768000, 738275586048000, 13386781384704000, 259936372452556800, 5427242941317120000
Offset: 1

Views

Author

Amarnath Murthy, Aug 05 2005

Keywords

Crossrefs

Cf. A111467, A111469.

Extensions

More terms from David Wasserman, Feb 10 2009

A111469 Row sums of A111467.

Original entry on oeis.org

1, 5, 30, 174, 1102, 8004, 64908, 631296, 7632144, 85538304, 767957760, 10378782720, 141810600960, 2211872624640, 34073996544000, 592443113472000, 9995136528384000, 193299238895616000, 3978509063587430400
Offset: 1

Views

Author

Amarnath Murthy, Aug 05 2005

Keywords

Crossrefs

Cf. A111467, A111468.

Extensions

More terms from David Wasserman, Feb 10 2009

A190107 Numbers with prime factorization pqr^2s^4.

Original entry on oeis.org

5040, 7920, 8400, 9360, 11088, 11340, 11760, 12240, 13104, 13200, 13680, 15600, 16560, 17136, 17820, 19152, 20400, 20592, 20880, 21060, 22320, 22800, 23184, 24948, 25872, 26640, 26928, 27540, 27600, 28350, 29040, 29232, 29484, 29520
Offset: 1

Views

Author

Vladimir Joseph Stephan Orlovsky, May 04 2011

Keywords

Comments

A050326(a(n)) = 3. - Reinhard Zumkeller, May 03 2013

Links

Crossrefs

Cf. A111467, A179704, A190106.

Programs

  • Mathematica
    f[n_]:=Sort[Last/@FactorInteger[n]]=={1,1,2,4};Select[Range[60000],f]
  • PARI
    list(lim)=my(v=List(),t1,t2,t3); forprime(p=2,sqrtnint(lim\60, 4), t1=p^4; forprime(q=2,sqrtint(lim\(6*t1)), if(q==p, next); t2=q^2*t1; forprime(r=2,lim\(2*t2), if(r==p || r==q, next); t3=r*t2; forprime(s=2,lim\t3, if(s==p || s==q || s==r, next); listput(v, t3*s))))); Set(v) \\ Charles R Greathouse IV, Aug 25 2016
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.