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.

A117166 Column 1 of triangle A117165 of Shift-Moebius coefficients and so equals the Shift-Moebius transform of [1,0,0,0,...].

Original entry on oeis.org

1, -1, -2, -1, -2, 1, -1, 3, 0, 4, 4, 5, 1, 7, 6, 5, 4, 6, 3, 5, 3, 2, 5, -3, -5, -1, 2, -7, -6, -13, -9, -14, -12, -22, -12, -25, -23, -26, -21, -35, -27, -38, -27, -43, -32, -47, -34, -51, -46, -52, -33, -53, -35, -58, -41, -56, -39, -54, -39, -61, -45, -53, -24, -46, -23, -44, -20, -41, -14, -32, -12, -22
Offset: 1

Views

Author

Wouter Meeussen and Paul D. Hanna, Mar 05 2006

Keywords

Comments

Equals the self-convolution inverse of A117161, which is the limit of columns of triangle A112682.

Crossrefs

Cf. A117165 (triangle), A117167 (column 2), A117168 (column 3), A117169 (row sums), A117161 (inverse), A117160, A112682.

Programs

  • PARI
    {a(n)=prod(i=0,n, matrix(n,n,r,c,if(r>=c,if((r+n-i)%(c+n-i)==0,moebius((r+n-i)/(c+n-i)),0))))[ n,1]}

A117169 Row sums of triangle A117165 of Shift-Moebius transform coefficients and so equals the Shift-Moebius transform of [1,1,1,...].

Original entry on oeis.org

1, 0, -1, -1, -2, -1, -2, 0, -2, 0, 1, 2, 0, 3, 3, 4, 4, 6, 5, 7, 6, 7, 10, 7, 4, 7, 10, 7, 8, 5, 7, 6, 6, 1, 5, 0, -1, -2, -1, -8, -6, -11, -7, -15, -12, -20, -15, -24, -27, -33, -25, -36, -28, -41, -39, -48, -42, -51, -46, -61, -61, -69, -58, -72, -64, -77, -70, -85, -76, -90, -85, -94, -86, -99, -84, -100
Offset: 1

Views

Author

Wouter Meeussen and Paul D. Hanna, Mar 05 2006

Keywords

Crossrefs

Cf. A117165 (triangle), A117166 (column 1), A117167 (column 2), A117168 (column 3); A117160.

Programs

  • PARI
    {a(n)=sum(j=1,n,prod(i=0,n+j-1,matrix(n+j-1,n+j-1,r,c,if(r>=c, if((r+n+j-1-i)%(c+n+j-1-i)==0,moebius((r+n+j-1-i)/(c+n+j-1-i)),0))))[n,j])}

A162696 Trajectory of 1 under morphism taking n to sorted divisors of n+1.

Original entry on oeis.org

1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 3, 1, 2, 1, 3, 1, 5, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 2, 3, 6, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 3, 1, 2, 1, 3, 1, 5, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2, 1, 3, 1, 2, 1, 3, 1, 5, 1, 2, 1, 3, 1, 2, 1, 3, 1, 2, 4, 1, 7, 1, 2, 1, 3, 1, 2, 1, 2, 4, 1, 2
Offset: 1

Views

Author

Keywords

Comments

1 -> 1,2; 2->1,3; 3->1,2,4; ...

Examples

			1 -> 1,2 -> 1,2,1,3 -> 1,2,1,3,1,2,1,2,4 -> ...
		

Crossrefs

Programs

  • PARI
    v=[1,2];for(i=2,60,v=concat(v,divisors(v[i]+1)));v

Formula

a(A117160(k+1)) = k (this is the first occurrence of k in the sequence). - Rémy Sigrist, Jan 14 2023
Showing 1-3 of 3 results.