|
Search: id:A125331
|
|
|
| A125331 |
|
Number of base 21 circular n-digit numbers with adjacent digits differing by 3 or less. |
|
+0
1
|
|
| 1, 21, 135, 693, 4159, 25291, 157635, 995659, 6357119, 40921479, 265145505, 1727138841, 11300204035, 74208972755, 488874737353, 3229363648333, 21382430152111, 141869013922279, 942972599847861, 6277675948529895
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
[Empirical] a(base,n)=a(base-1,n)+A025012(n+1) for base>=3.int(n/2)+1
|
|
PROGRAM
|
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>3)+($[(i+1)mod N]`-$[i]`>3))
|
|
CROSSREFS
|
Adjacent sequences: A125328 A125329 A125330 this_sequence A125332 A125333 A125334
Sequence in context: A008384 A110400 A089369 this_sequence A126489 A033595 A107731
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Ron Hardin (rhh(AT)cadence.com), Dec 28 2006
|
|
|
Search completed in 0.002 seconds
|
