|
|
A126487
|
|
Number of base 19 n-digit numbers with adjacent digits differing by three or less.
|
|
2
|
|
|
1, 19, 121, 791, 5217, 34587, 230033, 1533159, 10233063, 68367029, 457062389, 3057032825, 20453043685, 136869404619, 916044100681, 6131521065627, 41043887722493, 274756556545945, 1839334652522085, 12313523619477007
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
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.
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (1+8*x-64*x^2-36*x^3+236*x^4+91*x^5-231*x^6-80*x^7+63*x^8+18*x^9) / (1-11*x+24*x^2+48*x^3-96*x^4-77*x^5+96*x^6+49*x^7-27*x^8-9*x^9) (conjectured). - Colin Barker, Jul 18 2017
|
|
PROG
|
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>3)+($[i+1]`-$[i]`>3))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|