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.

A304737 Restricted growth sequence transform of A278222(A064413(n)).

Original entry on oeis.org

1, 1, 1, 2, 2, 3, 2, 1, 3, 3, 4, 3, 5, 5, 6, 2, 1, 3, 7, 7, 3, 8, 4, 7, 7, 5, 7, 7, 9, 3, 1, 3, 3, 8, 6, 7, 7, 9, 10, 3, 7, 9, 9, 6, 2, 7, 7, 8, 5, 7, 11, 4, 12, 3, 7, 9, 9, 13, 3, 14, 14, 13, 3, 1, 3, 6, 6, 15, 10, 9, 7, 3, 6, 6, 15, 6, 6, 10, 7, 10, 10, 3, 10, 16, 17, 7, 9, 18, 18, 10, 2, 7, 19, 7, 8, 8, 10, 8, 10, 10, 17, 9, 12, 5, 9
Offset: 1

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Author

Antti Karttunen, May 18 2018

Keywords

Comments

Sequence allots a distinct value for each distinct multiset formed from the lengths of 1-runs in the binary representation of A064413(n), the n-th term of EKG-sequence. Compare to the scatter plot of A286622.

Crossrefs

Programs

  • PARI
    \\ Needs also code for A064413.
    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));
    v304737 = rgs_transform(vector(65539,n,A278222(A064413(n))));
    A304737(n) = v304737[n];