OFFSET
1,1
EXAMPLE
252 is the smallest number such that 252 and its reverse (also 252) have 5 prime factors (2*2*3*3*7). So, a(5) = 252.
2576 is the smallest number such that 2576 and its reverse (6752) have 6 prime factors (2*2*2*2*7*23 and 2*2*2*2*2*211, respectively). So a(6) = 2576.
PROG
(Python)
import sympy
from sympy import factorint
def rev(x):
..rev = ''
..for i in str(x):
....rev = i + rev
..return int(rev)
def RevFact(x):
..n = 2
..while n < 10**8:
....if n % 10 != 0:
......if sum(list(factorint(n).values())) == x:
........if sum(list(factorint(rev(n)).values())) == x:
..........return n
........else:
..........n += 1
......else:
........n += 1
....else:
......n += 1
x = 1
while x < 100:
..print(RevFact(x))
..x += 1
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Derek Orr, Feb 15 2014
EXTENSIONS
a(17)-a(21) from Giovanni Resta, Feb 23 2014
a(22)-a(30) from Max Alekseyev, Feb 08 2024
STATUS
approved