A126493 Number of base 25 n-digit numbers with adjacent digits differing by three or less.

1, 25, 163, 1085, 7275, 48993, 330875, 2239053, 15174303, 102954301, 699137069, 4750953363, 32302586991, 219726864037, 1495133067339, 10176462578315, 69280311235399, 471736449047969, 3212552110817705, 21880121177493973

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

Table of n, a(n) for n=0..19.

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 25 differing by two or less A126412, one or less A126379.

Sequence in context: A139729 A317728 A125335 * A255419 A324899 A338892

Adjacent sequences: A126490 A126491 A126492 * A126494 A126495 A126496

Keyword

nonn,base

Author

R. H. Hardin, Dec 27 2006

Status

approved