A368062 Numbers k such that k = A257850(k) + A257297(k).

0, 36, 655, 1258, 6208, 12508, 45715, 65455, 75385, 125008, 235297, 1250008, 2857144, 3214288, 4210528, 6545455, 6792453, 12500008, 34615386, 47058824, 87671233, 125000008, 654545455, 1250000008, 9529411765, 12500000008, 39130434783, 45714285715, 65454545455, 75384615385

Offset

1,2

Links

Kevin Ryde, Table of n, a(n) for n = 1..700

Nicolas Bělohoubek, C# program

Nicolas Bělohoubek, Subsequences of form A-(B)-C

Kevin Ryde, PARI/GP Code

Example

     0 = 0*0   +   0*0;
    36 = 3*6   +   3*6;
   655 = 6*55  +  65*5;
  6208 = 6*208 + 620*8;
  ...

Mathematica

Select[Range[0, 10^6], Part[digits=IntegerDigits[#], 1]FromDigits[Drop[digits, 1]] + FromDigits[Drop[digits, -1]]Part[digits, Length[digits]] == # &] (* Stefano Spezia, Dec 10 2023 *)

Prog

(Python)
def ok(n):
    if n < 10: return n == 0
    s = str(n)
    return n == int(s[0])*int(s[1:]) + (n%10)*(n//10)
print([k for k in range(10**6) if ok(k)]) # Michael S. Branicky, Dec 10 2023
(Python) # faster for generating initial segment of sequence
from itertools import count, islice
def agen(): # generator of terms
    yield 0
    for digits in count(2):
        for first in range(1, 10):
            base = first*10**(digits-1)
            for rest in range(10**(digits-1)):
                n = base + rest
                if first*rest + (n%10)*(n//10) == n:
                    yield n
            print("...", digits, first, time()-time0, alst)
print(list(islice(agen(), 18))) # Michael S. Branicky, Dec 10 2023
(PARI) See links.

Crossrefs

Cf. A257850, A257297.

Sequence in context: A035713 A035478 A250624 * A231767 A278277 A188305

Adjacent sequences: A368059 A368060 A368061 * A368063 A368064 A368065

Keyword

nonn,base

Author

Nicolas Bělohoubek, Dec 10 2023

Extensions

a(24)-a(30) from Michael S. Branicky, Dec 10 2023

Status

approved