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A333670 Numbers m such that m equals abs(d_1^k - d_2^k + d_3^k - d_4^k ...), where d_i is the decimal expansion of m and k is some power greater than 2.

%I A333670 #26 May 10 2025 11:28:31
%S A333670 0,1,48,240,407,5920,5921,2918379,7444416,18125436,210897052,
%T A333670 6303187514,8948360198,10462450356,11647261846,18107015789,
%U A333670 27434621679,31332052290,4986706842391,485927682264092,1287253463537089,126835771455251081,559018292730428520,559018292730428521
%N A333670 Numbers m such that m equals abs(d_1^k - d_2^k + d_3^k - d_4^k ...), where d_i is the decimal expansion of m and k is some power greater than 2.
%C A333670 For terms > 1, the exponents k are 2, 4, 3, 4, 4, 7, 8, 8, 11, 11, 21, 11, 11, 11, 11, 13, 15, 16, 22, 21, 21.
%e A333670 48 = abs(4^2 - 8^2), 5920 = abs(5^4 - 9^4 + 2^4 - 0^4).
%o A333670 (Python)
%o A333670 def moda(n,a):
%o A333670     kk,j = 0,1
%o A333670     while n > 0:
%o A333670         kk= kk-j*(n%10)**a
%o A333670         n,j =int(n//10),-j
%o A333670     return abs(kk)
%o A333670 for i in range (0,10**7):
%o A333670     for t in range(2,21):
%o A333670         if i==moda(i,t):
%o A333670             print (i)
%o A333670             break
%Y A333670 Cf. A005188, A007770, A023052.
%K A333670 nonn,base
%O A333670 1,3
%A A333670 _Pieter Post_, Apr 01 2020
%E A333670 a(19)-a(24) from _Giovanni Resta_, Apr 02 2020