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 1-2 of 2 results.

A172382 Diagonal sums of number triangle A172380.

Original entry on oeis.org

1, 0, 1, 1, 3, 8, 25, 84, 301, 1139, 4528, 18849, 81968, 371622, 1753164, 8589608, 43624741, 229255133, 1244544545, 6968765313, 40195073827, 238527741350, 1454722738679, 9108812009826, 58503226812174, 385086101416594
Offset: 0

Views

Author

Paul Barry, Feb 01 2010

Keywords

Comments

a(n+2) gives the diagonal sums of A172381.

A172381 Triangle whose inverse has production matrix with general term (-1)^(n-k+1)*C(k+1, n-k+1).

Original entry on oeis.org

1, 1, 1, 2, 3, 1, 5, 10, 6, 1, 14, 36, 31, 10, 1, 42, 137, 156, 75, 15, 1, 132, 544, 787, 510, 155, 21, 1, 429, 2235, 4017, 3331, 1380, 287, 28, 1, 1430, 9445, 20809, 21405, 11411, 3255, 490, 36, 1, 4862, 40876, 109486, 136921, 90665, 33390, 6916, 786, 45, 1, 16796
Offset: 0

Views

Author

Paul Barry, Feb 01 2010

Keywords

Comments

Product of A033184 and A172380. Diagonal sums are A172382(n+2).

Examples

			Triangle begins
1,
1, 1,
2, 3, 1,
5, 10, 6, 1,
14, 36, 31, 10, 1,
42, 137, 156, 75, 15, 1,
132, 544, 787, 510, 155, 21, 1,
429, 2235, 4017, 3331, 1380, 287, 28, 1,
1430, 9445, 20809, 21405, 11411, 3255, 490, 36, 1,
4862, 40876, 109486, 136921, 90665, 33390, 6916, 786, 45, 1,
16796, 180544, 584955, 877252, 704720, 322728, 86443, 13536, 1200, 55, 1
Production array of inverse is
-1, 1,
0, -2, 1,
0, 1, -3, 1,
0, 0, 3, -4, 1,
0, 0, -1, 6, -5, 1,
0, 0, 0, -4, 10, -6, 1,
0, 0, 0, 1, -10, 15, -7, 1,
0, 0, 0, 0, 5, -20, 21, -8, 1,
0, 0, 0, 0, -1, 15, -35, 28, -9, 1,
0, 0, 0, 0, 0, -6, 35, -56, 36, -10, 1,
0, 0, 0, 0, 0, 1, -21, 70, -84, 45, -11, 1
		
Showing 1-2 of 2 results.