|
| |
|
|
A038508
|
|
Expansion of (1-2*x-x^2)/(1-4*x+2*x^2+4*x^3).
|
|
2
| |
|
|
1, 2, 5, 12, 30, 76, 196, 512, 1352, 3600, 9648, 25984, 70240, 190400, 517184, 1406976, 3831936, 10445056, 28488448, 77735936, 212186624, 579320832, 1581966336, 4320477184, 11800692736, 32233951232
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| Number of (s(0), s(1), ..., s(n+1)) such that 0 < s(i) < 6 and |s(i) - s(i-1)| <= 1 for i = 1,2,....,n+1, s(0) = 1, s(n+1) = 2. - Herbert Kociemba (kociemba(AT)t-online.de), Jun 17 2004
|
|
|
FORMULA
| a(n)=(3*2^(n+1) - Sqrt[3](1-Sqrt[3])^(n+1) + Sqrt[3](1+Sqrt[3])^(n+1))/12 - Herbert Kociemba (kociemba(AT)t-online.de), Jun 17 2004
|
|
|
CROSSREFS
| First differences are in A094297.
Sequence in context: A108360 A051163 A051450 * A002026 A105695 A026938
Adjacent sequences: A038505 A038506 A038507 * A038509 A038510 A038511
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
| |
|
|
