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.

A304097 Restricted growth sequence transform of A278222(A302853(n)).

Original entry on oeis.org

1, 2, 3, 2, 3, 2, 3, 2, 4, 5, 4, 6, 7, 2, 4, 5, 4, 5, 4, 6, 3, 5, 8, 5, 9, 4, 6, 7, 5, 10, 11, 10, 12, 2, 4, 5, 4, 5, 4, 5, 4, 11, 13, 11, 10, 14, 4, 11, 13, 11, 13, 11, 10, 5, 13, 15, 13, 16, 11, 10, 14, 13, 12, 17, 12, 2, 4, 11, 4, 5, 4, 5, 3, 5, 10, 6, 7, 9, 3, 5, 13, 5, 8, 5, 10, 6, 10, 14, 7, 16, 11, 13, 14, 13, 18, 2, 4, 5, 4, 5, 4, 5, 4, 11, 13, 11
Offset: 0

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Author

Antti Karttunen, May 17 2018

Keywords

Crossrefs

Compare also the scatter-plot to that of A304535.

Programs

  • PARI
    \\ Needs also code from A282291 and A302853:
    write_to_bfile(start_offset,vec,bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); }
    rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
    A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t };
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
    A278222(n) = A046523(A005940(1+n));
    write_to_bfile(0,rgs_transform(vector(60823,n,A278222(A302853(n-1)))),"b304097.txt");