|
|
A126403
|
|
Number of base 16 n-digit numbers with adjacent digits differing by two or less.
|
|
3
|
|
|
1, 16, 74, 350, 1668, 7986, 38348, 184524, 889230, 4290030, 20714382, 100083072, 483793208, 2339478320, 11316186924, 54748710158, 264922095330, 1282082867386, 6205185792886, 30034782040334, 145384379570694
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
COMMENTS
|
[Empirical] a(base,n)=a(base-1,n)+5^(n-1) for base>=2n-1; a(base,n)=a(base-1,n)+5^(n-1)-2 when base=2n-2.
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (1+7*x-51*x^2+4*x^3+131*x^4+10*x^5-61*x^6-2*x^7+3*x^8) / (1-9*x+19*x^2+16*x^3-49*x^4-14*x^5+23*x^6+2*x^7-x^8) (conjectured). - Colin Barker, Jul 18 2017
|
|
PROG
|
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>2)+($[i+1]`-$[i]`>2))
|
|
CROSSREFS
|
Cf. Base 16 differing by one or less A126370.
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|