login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A271592 Array read by antidiagonals: T(n,m) = number of directed Hamiltonian walks from NW to SW corners on a grid with n rows and m columns. 7
1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 2, 1, 1, 0, 1, 0, 4, 0, 1, 0, 1, 4, 8, 8, 1, 1, 0, 1, 0, 23, 0, 16, 0, 1, 0, 1, 8, 55, 86, 47, 32, 1, 1, 0, 1, 0, 144, 0, 397, 0, 64, 0, 1, 0, 1, 16, 360, 948, 1770, 1584, 264, 128, 1, 1, 0, 1, 0, 921, 0, 11658, 0, 6820, 0, 256, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,13

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..378

FORMULA

T(n,m)=0 for n odd and m even, T(1,n)=0 for n>1.

T(2,n)=T(n,1)=T(2*n,2)=1, T(3,2*n+1)=T(n+1,3)=2^n.

EXAMPLE

The start of the sequence as table:

* 1 0   0   0     0     0       0       0          0 ...

* 1 1   1   1     1     1       1       1          1 ...

* 1 0   2   0     4     0       8       0         16 ...

* 1 1   4   8    23    55     144     360        921 ...

* 1 0   8   0    86     0     948       0      10444 ...

* 1 1  16  47   397  1770   11658   59946     359962 ...

* 1 0  32   0  1584     0   88418       0    4999752 ...

* 1 1  64 264  6820 52387  909009 8934966  130373192 ...

* 1 0 128   0 28002     0 7503654       0 2087813834 ...

* ...

CROSSREFS

Main diagonal is A000532. Rows include A181688, A181689.

Column 4 is aerated A014524, column 5 is A014585.

Sequence in context: A035155 A090584 A171400 * A128409 A133699 A157361

Adjacent sequences:  A271589 A271590 A271591 * A271593 A271594 A271595

KEYWORD

nonn,tabl

AUTHOR

Andrew Howroyd, Apr 10 2016

STATUS

approved

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 12 15:11 EST 2019. Contains 329960 sequences. (Running on oeis4.)