[go: up one dir, main page]

login
A126541
Number of base 20 n-digit numbers with adjacent digits differing by five or less.
0
1, 20, 190, 1870, 18600, 185922, 1862204, 18667904, 187205534, 1877615174, 18833087302, 188906865160, 1894866747430, 19006912484080, 190653725780160, 1912402757442222, 19182869344924714, 192418948095124214
OFFSET
0,2
COMMENTS
[Empirical] a(base,n)=a(base-1,n)+11^(n-1) for base>=5n-4; a(base,n)=a(base-1,n)+11^(n-1)-2 when base=5n-5
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>5)+($[i+1]`-$[i]`>5))
CROSSREFS
Cf. Base 20 differing by four or less A126515, three or less A126488, two or less A126407, one or less A126374.
Sequence in context: A171075 A061180 A125383 * A213218 A247742 A355590
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 28 2006
STATUS
approved