A126398 Number of base 11 n-digit numbers with adjacent digits differing by two or less.

1, 11, 49, 225, 1043, 4861, 22723, 106401, 498703, 2338691, 10970731, 51472161, 241518759, 1133320429, 5318237121, 24956866179, 117116084385, 549598276829, 2579143380799, 12103370927679, 56798597444915, 266544122924215

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..21.

Formula

G.f.: (1+4*x-19*x^2-8*x^3+19*x^4+x^5-2*x^6) / (1-7*x+9*x^2+11*x^3-11*x^4-2*x^5+x^6) (conjectured). - Colin Barker, Jul 17 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 11 differing by one or less A126365.

Sequence in context: A003063 A124857 A302473 * A159486 A284857 A241964

Adjacent sequences: A126395 A126396 A126397 * A126399 A126400 A126401

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved