A037912 Number of i such that |d(i) - d(i-1)| = 1, where Sum_{i=0..m} d(i)*9^i is the base-9 representation of n.

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1

Offset

1,82

Links

Iain Fox, Table of n, a(n) for n = 1..10000

Prog

(PARI) a(n) = my(c); for(i=2, #n=digits(n, 9), if(abs(n[i]-n[i-1])==1, c++)); c

Crossrefs

In base b: A037906 (b=3), A037907 (b=4), A037908 (b=5), A037909 (b=6), A037910 (b=7), A037911 (b=8), A037913 (b=10).

Sequence in context: A037911 A176046 A172090 * A056980 A268643 A005094

Adjacent sequences: A037909 A037910 A037911 * A037913 A037914 A037915

Keyword

nonn,base

Author

Clark Kimberling

Status

approved