login
A082939
Numbers such that sum of the digits of the product of the factorial of digits of the number is equal to the sum of the digits of the number.
2
1, 2, 10, 18, 20, 22, 27, 36, 63, 72, 81, 100, 108, 114, 117, 126, 135, 141, 153, 162, 171, 180, 200, 202, 207, 216, 220, 261, 270, 306, 315, 333, 351, 360, 411, 513, 531, 603, 612, 621, 630, 702, 711, 720, 801, 810, 1000, 1008, 1014, 1017, 1026, 1035, 1041
OFFSET
1,2
REFERENCES
Suggested by Amarnath Murthy.
LINKS
FORMULA
Numbers k such that A007953(k) = A007953(A066459(k)).
EXAMPLE
63 = 6!*3! = 720*6 = 4320, 4 + 3 + 2 + 0 = 9 and 6 + 3 = 9.
PROG
(Python)
from math import factorial, prod
def ok(n):
d = list(map(int, str(n)))
return sum(map(int, str(prod(map(factorial, d))))) == sum(d)
print([k for k in range(1042) if ok(k)]) # Michael S. Branicky, Aug 15 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Meenakshi Srikanth (menakan_s(AT)yahoo.com), Apr 27 2003
EXTENSIONS
Corrected and extended by Jason Earls, May 22 2004
STATUS
approved