A319744 Partial sums of bouncy numbers (A152054).

101, 203, 306, 410, 515, 621, 728, 836, 945, 1065, 1186, 1316, 1447, 1579, 1719, 1860, 2002, 2145, 2295, 2446, 2598, 2751, 2905, 3065, 3226, 3388, 3551, 3715, 3880, 4050, 4221, 4393, 4566, 4740, 4915, 5091, 5271, 5452, 5634, 5817, 6001, 6186, 6372, 6559, 6749, 6940, 7132, 7325, 7519

Offset

1,1

Links

David F. Marrs, Table of n, a(n) for n = 1..10000

Example

a(1) = 101.
a(2) = 101 + 102 = 203.
a(10) = 101 + 102 + 103 + 104 + 105 + 106 + 107 + 108 + 109 + 120 = 1065.

Prog

(Python)
for n in range(50):
..a = n
..b = 0
..c = 0
..while a:
....if ''.join(sorted(str(b))) != str(b) and ''.join(sorted(str(b)))[::-1] != str(b): c += b; a -= 1
....b += 1
..print(c)
(Python)
from itertools import count, islice
def A319744_gen(): # generator of terms
    c = 0
    for n in count(101):
        l = len(s:=tuple(int(d) for d in str(n)))
        for i in range(1, l-1):
            if (s[i-1]-s[i])*(s[i]-s[i+1]) < 0:
                c += n
                yield c
                break
A319744_list = list(islice(A319744_gen(), 30)) # Chai Wah Wu, Jul 28 2023

Crossrefs

Cf. A152054 (bouncy numbers).

Sequence in context: A138131 A069858 A357033 * A303575 A171798 A067861

Adjacent sequences: A319741 A319742 A319743 * A319745 A319746 A319747

Keyword

nonn,base

Author

David F. Marrs, Oct 21 2018

Status

approved