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

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

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

Programs

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