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A126418
Number of base 31 n-digit numbers with adjacent digits differing by two or less.
4
1, 31, 149, 725, 3543, 17361, 85223, 418899, 2061105, 10149405, 50011235, 246566635, 1216199805, 6001382075, 29624479933, 146279954561, 722500541847, 3569422111283, 17638150070523, 87175432519409, 430936179702041
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
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 31 differing by one or less A126385.
Sequence in context: A234122 A142758 A124994 * A347109 A142792 A201964
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 28 2006
STATUS
approved