A106241 Triangle of coefficients arising in connection with enumeration of series-parallel networks.

1, 2, 2, 4, 16, 6, 8, 88, 116, 24, 16, 416, 1312, 888, 120

Offset

1,2

References

J. Riordan, The blossoming of Schroeder's fourth problem, Acta Math., 137 (1976), 1-16.

Links

Table of n, a(n) for n=1..15.

Example

Triangle begins:
1
2 2
4 16 6
8 88 116 24

Crossrefs

Sequence in context: A257609 A087783 A176190 * A153991 A153994 A102864

Adjacent sequences: A106238 A106239 A106240 * A106242 A106243 A106244

Keyword

nonn,tabl,more

Author

N. J. A. Sloane, May 29 2005

Status

approved