A126482 Number of base 14 n-digit numbers with adjacent digits differing by three or less.

1, 14, 86, 546, 3502, 22582, 146000, 945166, 6122674, 39674426, 257126690, 1666543060, 10801947152, 70015705526, 453829551820, 2941656640950, 19067428223036, 123592671411170, 801112565036276, 5192714887319794

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.

Formula

G.f.: (1+5*x-27*x^2-21*x^3+35*x^4+8*x^5-5*x^6-x^7) / (1-9*x+13*x^2+25*x^3-21*x^4-10*x^5+3*x^6+x^7) (conjectured). - Colin Barker, Jul 18 2017

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 14 differing by two or less A126401, one or less A126368.

Sequence in context: A372148 A213121 A125324 * A206614 A345107 A321941

Adjacent sequences: A126479 A126480 A126481 * A126483 A126484 A126485

Keyword

nonn,base

Author

R. H. Hardin, Dec 27 2006

Status

approved