login
A126499
Number of base 31 n-digit numbers with adjacent digits differing by three or less.
3
1, 31, 205, 1379, 9333, 63399, 431717, 2944947, 20115561, 137543107, 941258689, 6445801999, 44166431335, 302771722951, 2076414065529, 14244985903467, 97754711626643, 671000257052461, 4606822746884183, 31634499742407797
OFFSET
0,2
COMMENTS
[Empirical] a(base,n)=a(base-1,n)+7^(n-1) for base>=3n-2; a(base,n)=a(base-1,n)+7^(n-1)-2 when base=3n-3
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>3)+($[i+1]`-$[i]`>3))
CROSSREFS
Cf. Base 31 differing by two or less A126418, one or less A126385.
Sequence in context: A137657 A228220 A125341 * A297758 A184058 A096906
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 27 2006
STATUS
approved