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.

A078638 a(n) = rad(n*(n+1)*(n+2)*(n+3)).

Original entry on oeis.org

6, 30, 30, 210, 210, 42, 210, 330, 330, 4290, 6006, 2730, 2730, 3570, 510, 1938, 9690, 3990, 43890, 53130, 10626, 7590, 8970, 390, 2730, 15834, 6090, 188790, 26970, 10230, 34782, 39270, 39270, 132090, 147630, 54834, 274170, 303810, 111930
Offset: 1

Views

Author

Jon Perry, Dec 12 2002

Keywords

Examples

			a(3)=rad(3*4*5*6)=30.
		

Crossrefs

Cf. A007947.

Programs

  • PARI
    rad(n)=local(p,i); p=factor(n)[,1]; prod(i=1,length(p),p[i]) for (k=1,100,print1(rad(k*(k+1)*(k+2)*(k+3))","))
    
  • PARI
    a(n)=my(v=[]);for(i=0,3,v=concat(v,factor(n+i)[,1])); v=vecsort(v,,8); prod(i=1,#v,v[i]) \\ Charles R Greathouse IV, Jun 20 2013