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.

A140740 Triangle read by rows: T(n,n) = 1 and for k with 1 <= k < n: T(n+1,k) = T(n,k) + T(n - n mod k, k).

Original entry on oeis.org

1, 2, 1, 4, 2, 1, 8, 3, 2, 1, 16, 6, 3, 2, 1, 32, 9, 4, 3, 2, 1, 64, 18, 8, 4, 3, 2, 1, 128, 27, 12, 5, 4, 3, 2, 1, 256, 54, 16, 10, 5, 4, 3, 2, 1, 512, 81, 32, 15, 6, 5, 4, 3, 2, 1, 1024, 162, 48, 20, 12, 6, 5, 4, 3, 2, 1, 2048, 243, 64, 25, 18, 7, 6, 5, 4, 3, 2, 1, 4096, 486, 128, 50, 24
Offset: 1

Views

Author

Reinhard Zumkeller, May 26 2008

Keywords

Comments

Central terms: T(2*n-1,n)=n; T(2*n,n)=n+1; T(2*n,n+1)=n;
T(n,k) = n-k+1, for k with n/2 <= k <= n;
sums of rows: A140741;
T(n,1) = A000079(n-1);
T(n,2) = A038754(n-2) for n>1;
T(n,3) = A133464(n-3) for n>2;
T(n,4) = A140730(n-4) for n>3;
T(n,9) = A037124(n-9) for n>8.

Examples

			.................................... 1
.................................. 2 . 1
.............................. 2^2 . 2 . 1
.......................... 2^3 ... 3 . 2 . 1
...................... 2^4 ... 2*3 . 3 . 2 . 1
.................. 2^5 ... 3^2 ... 4 . 3 . 2 . 1
.............. 2^6 .. 2*3^2 .. 2*4 . 4 . 3 . 2 . 1
.......... 2^7 ... 3^3 ... 3*4 ... 5 . 4 . 3 . 2 . 1
...... 2^8 .. 2*3^3 ... 4^2 .. 2*5 . 5 . 4 . 3 . 2 . 1
... 2^9 ... 3^4 .. 2*4^2 . 3*5 ... 6 . 5 . 4 . 3 . 2 . 1
2^10 . 2*3^4 . 3*4^2 .. 4*5 .. 2*6 . 6 . 5 . 4 . 3 . 2 . 1.