A143774 Eigentriangle of triangle A022166.

1, 1, 1, 1, 3, 2, 1, 7, 14, 6, 1, 15, 70, 70, 28, 1, 31, 310, 930, 868, 204, 1, 63, 1302, 8370, 18228, 12852, 2344

Offset

0,5

Comments

An eigentriangle of triangle T may be defined by taking the termwise product of row n-1 of T and the first n terms of the eigensequence of T; 0<=k<=n.

Row sums = A125812 shifted 1 place to the left: (1, 2, 6, 28, 204,...).

Sum of n-th row terms = rightmost term of (n+1)-th row.

1, 1;

1, 3, 1;

1, 7, 7, 1;

1, 15, 35, 15, 1;

... (and the eigensequence of A022166 = A125812: (1, 1, 2, 6, 28, 204,...) we apply the termwise product of (n-1)-th row of A022166 and the first n terms of A125812.

Links

Table of n, a(n) for n=0..27.

Formula

Given triangle A022166: 1;

Example

First few rows of the triangle:
  1;
  1, 1;
  1, 3, 2;
  1, 7, 14, 6;
  1, 15, 70, 90, 28;
  1, 31, 310, 930, 868, 204;
  ...
Row 3 of A022166 = (1, 7, 7, 1), first 4 terms of A143774 = (1, 1, 2, 6), so row 3 of A143774 = (1*1, 7*1, 7*2, 1*6) = (1, 7, 14, 6).

Crossrefs

Cf. A022166, A125812.

Sequence in context: A163626 A028246 A082038 * A196842 A158474 A090452

Adjacent sequences: A143771 A143772 A143773 * A143775 A143776 A143777

Keyword

nonn,tabl,more

Author

Gary W. Adamson, Aug 31 2008

Status

approved