A356961 - OEIS

A356961

Integers k such that A014841(k) = A014841(k+1).

8, 16, 64, 104, 3954, 4146, 7374, 9294, 28035, 35166, 37218, 38154, 39318, 40578, 42308, 42774, 48748, 50214, 67638, 68106, 75918, 78882, 87294, 87836, 89382, 90642, 94074, 96124, 102822, 107324, 108294, 108534, 118016, 118806, 131046, 153798, 157254, 163182, 166494, 168486

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..40.

MATHEMATICA

f[n_]:=Sum[Mod[Total[IntegerDigits[n, i]], i], {i, 2, n-1}]; kmax=97000; a={}; For[k=3, k<=kmax, k++, If[f[k]==f[k+1], AppendTo[a, k]]]; a (* Stefano Spezia, Sep 06 2022 *)

PROG

(PARI) f(n) = sum(b=2, n-1, sumdigits(n, b) % b); \\ A014841

isok(k) = f(k) == f(k+1);

(Python)

from sympy.ntheory import digits

from itertools import count, islice

def f(n): return sum(sum(digits(n, b)[1:])%b for b in range(2, n))

def agen(): # generator of terms

f0, f1 = f(3), f(4)

for k in count(3):

if f0 == f1: yield k

f0, f1, = f1, f(k+2)