A124947 Number of base 19 circular n-digit numbers with adjacent digits differing by 2 or less.

1, 19, 89, 331, 1437, 6289, 28241, 128413, 590197, 2734297, 12749679, 59763613, 281370909, 1329632401, 6303226767, 29963180101, 142776168261, 681776377177, 3261689820791, 15630400760077, 75015245736567, 360509440244557

Offset

0,2

Comments

[Empirical] a(base,n)=a(base-1,n)+A005191(n+1) for base>=2.int(n/2)+1.

See A285280 for confirmation of linear recurrence and code to produce sequence. - Ray Chandler, Aug 12 2023.

Links

Ray Chandler, Table of n, a(n) for n = 0..99

Index entries for linear recurrences with constant coefficients, signature (19, -136, 408, -125, -1987, 3002, 3146, -8052, -1870, 9565, -23, -5762, 442, 1720, -150, -220, 16, 8).

Prog

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

Crossrefs

Cf. Row 19 of A285280.

Sequence in context: A039454 A142089 A174819 * A126406 A201306 A160296

Adjacent sequences: A124944 A124945 A124946 * A124948 A124949 A124950

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved