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A126398 Number of base 11 n-digit numbers with adjacent digits differing by two or less. 3
1, 11, 49, 225, 1043, 4861, 22723, 106401, 498703, 2338691, 10970731, 51472161, 241518759, 1133320429, 5318237121, 24956866179, 117116084385, 549598276829, 2579143380799, 12103370927679, 56798597444915, 266544122924215 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 15 15:16 EDT 2021. Contains 345049 sequences. (Running on oeis4.)