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 1-5 of 5 results.

A292251 The 3-adic valuation of A048673(n).

Original entry on oeis.org

0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 2, 0, 1, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 4, 0, 1, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0
Offset: 1

Views

Author

Antti Karttunen, Sep 12 2017

Keywords

Crossrefs

One less than the even bisection of A292252.
Cf. also A292241, A292261.

Programs

  • Mathematica
    IntegerExponent[#, 3] & /@ Table[(Times @@ Power[If[# == 1, 1, NextPrime@ #] & /@ First@ #, Last@ #] + 1)/2 &@ Transpose@ FactorInteger@ n, {n, 120}] (* Michael De Vlieger, Sep 12 2017 *)

Formula

a(n) = A007814(1+A292250(n)).
a(n) = A007949(A048673(n)).
a(n) = A007949(3*A048673(n)) - 1.
a(n) = A292252(2n)-1.

A292261 The 3-adic valuation of A245612(n).

Original entry on oeis.org

0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 3, 0, 0, 0, 2, 0, 1, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0
Offset: 0

Views

Author

Antti Karttunen, Sep 12 2017

Keywords

Crossrefs

One less than the even bisection of A292262.
Cf. also A292241, A292251.

Formula

a(n) = A007814(1+A292260(n)).
a(n) = A007949(A245612(n)).
For n >= 1, a(n) = A007949(3*A245612(n)) - 1.
For n >= 1, a(n) = A292262(2n)-1.

A292240 Binary encoding of 0-digits in ternary representation of A254103(n).

Original entry on oeis.org

0, 0, 0, 1, 0, 0, 0, 1, 0, 3, 2, 0, 0, 0, 0, 2, 0, 0, 0, 1, 4, 3, 2, 1, 0, 3, 2, 1, 0, 7, 6, 0, 0, 3, 2, 4, 0, 0, 0, 1, 8, 0, 0, 6, 4, 4, 4, 2, 0, 8, 8, 6, 4, 4, 4, 5, 0, 0, 0, 1, 12, 3, 2, 0, 0, 8, 8, 9, 4, 11, 10, 0, 0, 3, 2, 4, 0, 0, 0, 2, 16, 3, 2, 1, 0, 15, 14, 0, 8, 11, 10, 1, 8, 7, 6, 5, 0, 19, 18, 1, 16, 15, 14, 13, 8, 11
Offset: 0

Views

Author

Antti Karttunen, Sep 12 2017

Keywords

Crossrefs

Formula

a(n) = A291770(A254103(n)).

A292242 Number of trailing 2-digits in ternary representation of A254103(n).

Original entry on oeis.org

0, 0, 1, 0, 1, 0, 2, 0, 1, 0, 1, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 1, 0, 1, 0, 3, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 2, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 2, 0, 1, 0, 1, 0, 1, 0, 2, 0, 1
Offset: 0

Views

Author

Antti Karttunen, Sep 12 2017

Keywords

Crossrefs

Cf. A007814, A007949, A254103, A291760, A292241 (even bisection subtracted by one).
Cf. also A292252, A292262.

Programs

Formula

a(n) = A007949(1+A254103(n)).
a(n) = A007814(1+A291760(n)).
a(0) = 0, after which, a(2n) = 1 + A292241(n/2), a(2n+1) = 0.

A304750 Restricted growth sequence transform of A292240(n), formed from 0-digits in ternary representation of A254103(n).

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 1, 2, 1, 3, 4, 1, 1, 1, 1, 4, 1, 1, 1, 2, 5, 3, 4, 2, 1, 3, 4, 2, 1, 6, 7, 1, 1, 3, 4, 5, 1, 1, 1, 2, 8, 1, 1, 7, 5, 5, 5, 4, 1, 8, 8, 7, 5, 5, 5, 9, 1, 1, 1, 2, 10, 3, 4, 1, 1, 8, 8, 11, 5, 12, 13, 1, 1, 3, 4, 5, 1, 1, 1, 4, 14, 3, 4, 2, 1, 15, 16, 1, 8, 12, 13, 2, 8, 6, 7, 9, 1, 17, 18, 2, 14, 15, 16, 19, 8, 12
Offset: 0

Views

Author

Antti Karttunen, May 30 2018

Keywords

Comments

For all i, j: a(i) = a(j) => A292241(i) = A292241(j).

Crossrefs

Programs

  • PARI
    A254103(n) = if(!n,n,if(!(n%2),(3*A254103(n/2))-1,(3*(1+A254103((n-1)/2)))\2));
    A291770(n) = { my(s=0, b=1, d); while(n>2, if(!(n%3), s += b); b <<= 1; n \= 3); (s); };
    A292240(n) = A291770(A254103(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; };
    v304750 = rgs_transform(vector(65538,n,A292240(n-1)));
    A304750(n) = v304750[1+n];
Showing 1-5 of 5 results.