A354710 Records in A009101.
0, 102, 110, 140, 150, 170, 209, 210, 260, 330, 4506, 11620, 17054, 19008, 20979, 24120, 27780, 32305, 32805, 34590, 42012, 52054, 55048, 59049, 65610, 70536, 75006, 90432, 111006, 112050, 118098, 120594, 136052, 150297, 153302, 160824, 181039, 183708, 208044
Offset: 0
Crossrefs
Cf. A009101.
Programs
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Python
import numpy input_list = [] output_list = [] max_list = [] range_ = 10 ** 7 lower = 0 upper = lower + range_ for i in range(lower, upper): input_list.append(i) number = str(i) results_list = [] total = 0 total_list = [] while True: number_list = [] for x in list(number): number_list.append(int(x)) results_list.append(numpy.prod(number_list)) total += numpy.prod(number_list) if total in total_list: output_list.append(total_list[-1]) if total_list[-1] >= max(output_list): if total_list[-1] not in max_list: max_list.append(total_list[-1]) break total_list.append(total) number = str(total) print(max_list) -
Python
from math import prod from itertools import count, islice def pd(n): return prod(map(int, str(n))) def f(x): return x + pd(x) def agen(): # generator of terms record, seen = -1, set() for n in count(0): x = pd(n) if x in seen: continue seen.add(x) fx = f(x) while x != fx: x, fx = fx, f(fx) if fx > record: record = fx yield record print(list(islice(agen(), 39))) # Michael S. Branicky, Jun 21 2022