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A126367 Number of base 13 n-digit numbers with adjacent digits differing by one or less. 4
1, 13, 37, 107, 311, 907, 2651, 7761, 22749, 66747, 195995, 575893, 1693073, 4979777, 14652601, 43128637, 126982109, 373962395, 1101557803, 3245398895, 9563118423, 28183332105, 83068897785, 244867352543, 721877651203 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

[Empirical] a(base,n)=a(base-1,n)+3^(n-1) for base>=n; a(base,n)=a(base-1,n)+3^(n-1)-2 when base=n-1

LINKS

Table of n, a(n) for n=0..24.

FORMULA

Empirical G.f.: -(4*x^7-23*x^6-38*x^5+59*x^4+30*x^3-40*x^2+6*x+1) / ((x-1)*(x^6-6*x^5-13*x^4+8*x^3+8*x^2-6*x+1)). [Colin Barker, Nov 26 2012]

PROG

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>1)+($[i+1]`-$[i]`>1))

CROSSREFS

Sequence in context: A331763 A155263 A155228 * A139926 A155259 A155308

Adjacent sequences:  A126364 A126365 A126366 * A126368 A126369 A126370

KEYWORD

nonn,base

AUTHOR

R. H. Hardin, Dec 26 2006

STATUS

approved

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Last modified February 20 04:34 EST 2020. Contains 332063 sequences. (Running on oeis4.)