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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.
0
0, 1, 48, 240, 407, 5920, 5921, 2918379, 7444416, 18125436, 210897052, 6303187514, 8948360198, 10462450356, 11647261846, 18107015789, 27434621679, 31332052290, 4986706842391, 485927682264092, 1287253463537089, 126835771455251081, 559018292730428520, 559018292730428521
OFFSET
1,3
COMMENTS
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.
EXAMPLE
48 = abs(4^2 - 8^2), 5920 = abs(5^4 - 9^4 + 2^4 - 0^4).
PROG
(Python)
def moda(n, a)
kk, j = 0, 1
while n > 0:
kk= kk-j*(n%10)**a
n, j =int(n//10), -j
return abs(kk)
for i in range (0, 10**12):
for t in range(2, 21):
if i==moda(i, t):
print (i, t, moda(i, t))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Pieter Post, Apr 01 2020
EXTENSIONS
a(19)-a(24) from Giovanni Resta, Apr 02 2020
STATUS
approved