A032857 - OEIS

A032857

Numbers whose base-10 representation Sum_{i=0..m} d(i)*10^i, d(m) > 0, has d(m) <= d(m-1) >= d(m-2) <= ...

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 22, 23, 24, 25, 26, 27, 28, 29, 33, 34, 35, 36, 37, 38, 39, 44, 45, 46, 47, 48, 49, 55, 56, 57, 58, 59, 66, 67, 68, 69, 77, 78, 79, 88, 89, 99, 110, 111, 120, 121, 122, 130, 131

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

The second digit must be greater than or equal to the first, the third digit must be less than or equal to the second, etc. - M. F. Hasler, Mar 08 2014

LINKS

Table of n, a(n) for n=1..61.

PROG

(PARI) is_A032857(n)=!for(i=2, #n=digits(n), (n[i]-n[i-1])*(-1)^i<0&&return) \\ M. F. Hasler, Mar 08 2014

CROSSREFS

Sequence in context: A227510 A032898 A131058 * A072544 A009994 A239016

Adjacent sequences: A032854 A032855 A032856 * A032858 A032859 A032860

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved