A350779 Indices where Iccanobif numbers of the form A014258 decrease, i.e., numbers k such that A014258(k) < A014258(k-1).

10, 17, 19, 20, 21, 23, 28, 31, 32, 39, 41, 45, 50, 55, 58, 60, 66, 70, 73, 75, 78, 83, 84, 90, 92, 95, 100, 101, 103, 105, 113, 114, 117, 123, 126, 129, 131, 140, 143, 147, 149, 151, 153, 155, 157, 163, 166, 167, 174, 176, 184, 197, 200, 206, 208, 210, 215, 217

Offset

1,1

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Example

A014258(17) = 715297 < 739401 = A014258(16), so 17 is a term.

Mathematica

Flatten[Position[s, #]&/@Select[s=NestList[{Last@#, FromDigits@Reverse@IntegerDigits@Total@#}&, {0, 1}, 220], !OrderedQ@#&]]  (* Giorgos Kalogeropoulos, Jan 16 2022 *)

Prog

(Python)
from itertools import count, islice
def A350079_gen(): # generator of terms
    a, b = 0, 1
    for n in count(1):
        if b < a:
            yield n
        a, b = b, int(str(a+b)[::-1])
A350079_list = list(islice(A350079_gen(), 20))

Crossrefs

Cf. A014258.

Sequence in context: A256346 A079630 A175389 * A280591 A308691 A332226

Adjacent sequences: A350776 A350777 A350778 * A350780 A350781 A350782

Keyword

nonn,base,easy

Author

Chai Wah Wu, Jan 15 2022

Status

approved