A126406 Number of base 19 n-digit numbers with adjacent digits differing by two or less.

1, 19, 89, 425, 2043, 9861, 47723, 231399, 1123605, 5461905, 26573735, 129379137, 630262495, 3071700043, 14976139061, 73039059807, 356304015623, 1738508587487, 8484132138387, 41409427571489, 202134928523711

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

Table of n, a(n) for n=0..20.

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 19 differing by one or less A126373.

Sequence in context: A142089 A174819 A124947 * A201306 A160296 A347364

Adjacent sequences: A126403 A126404 A126405 * A126407 A126408 A126409

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved