The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A122176 Triangle, read by rows, where T(n,k) = C( k*(k+1)/2 + n-k + 1, n-k) for n>=k>=0. 6
 1, 2, 1, 3, 3, 1, 4, 6, 5, 1, 5, 10, 15, 8, 1, 6, 15, 35, 36, 12, 1, 7, 21, 70, 120, 78, 17, 1, 8, 28, 126, 330, 364, 153, 23, 1, 9, 36, 210, 792, 1365, 969, 276, 30, 1, 10, 45, 330, 1716, 4368, 4845, 2300, 465, 38, 1, 11, 55, 495, 3432, 12376, 20349, 14950, 4960, 741, 47, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Remarkably, column k of the matrix inverse (A121436) equals signed column k of matrix power: A107876^(k*(k+1)/2 + 2). LINKS Harvey P. Dale, Table of n, a(n) for n = 0..10000 EXAMPLE Triangle begins: 1; 2, 1; 3, 3, 1; 4, 6, 5, 1; 5, 10, 15, 8, 1; 6, 15, 35, 36, 12, 1; 7, 21, 70, 120, 78, 17, 1; 8, 28, 126, 330, 364, 153, 23, 1; 9, 36, 210, 792, 1365, 969, 276, 30, 1; ... MATHEMATICA Flatten[Table[Binomial[(k(k+1))/2+n-k+1, n-k], {n, 0, 10}, {k, 0, n}]] (* Harvey P. Dale, Mar 18 2013 *) PROG (PARI) T(n, k)=if(n

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 23 16:01 EDT 2020. Contains 337310 sequences. (Running on oeis4.)