A126536 - OEIS

A126536

Number of base 15 n-digit numbers with adjacent digits differing by five or less.

1, 15, 135, 1265, 11945, 112969, 1068723, 10111095, 95661377, 905057497, 8562802623, 81013191559, 766470702689, 7251625683041, 68608069306975, 649105094579799, 6141222571633425, 58102478303643985, 549711062520950431

(list; graph; refs; listen; history; text; internal format)

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.

LINKS

Table of n, a(n) for n=0..18.

FORMULA

G.f.: (1+5*x-14*x^2-30*x^3+22*x^4+30*x^5-8*x^6-8*x^7) / (1-10*x+x^2+40*x^3-8*x^4-34*x^5+4*x^6+8*x^7) (conjectured). - Colin Barker, Jul 19 2017

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 15 differing by four or less A126510, three or less A126483, two or less A126402, one or less A126369.

Sequence in context: A125378 A254409 A155648 * A299033 A030056 A225978

Adjacent sequences: A126533 A126534 A126535 * A126537 A126538 A126539

KEYWORD

nonn,base

AUTHOR

R. H. Hardin, Dec 28 2006

STATUS

approved