|
Search: id:A125432
|
|
|
| A125432 |
|
Number of base 20 circular n-digit numbers with adjacent digits differing by 7 or less. |
|
+0
1
|
|
| 1, 20, 244, 2540, 30372, 371020, 4624618, 58276910, 739421468, 9420320720, 120311299494, 1538801863322, 19698661301598, 252298551792242, 3232403330179960, 41420461452496840, 530824357422030924
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
[Empirical] a(base,n)=a(base-1,n)+F(7) for base>=7.int(n/2)+1, and F(d) is the largest coefficient in (1+x+...+x^(2d))^n
|
|
PROGRAM
|
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>7)+($[(i+1)mod N]`-$[i]`>7))
|
|
CROSSREFS
|
Adjacent sequences: A125429 A125430 A125431 this_sequence A125433 A125434 A125435
Sequence in context: A138442 A140124 A123954 this_sequence A055757 A022744 A081143
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Ron Hardin (rhh(AT)cadence.com), Dec 28 2006
|
|
|
Search completed in 0.002 seconds
|
