

A229804


Zeroless numbers n such that n and n*product_of_digits(n) are both palindromes.


1



1, 2, 3, 11, 22, 77, 111, 121, 131, 212, 464, 1111, 1221, 2112, 11111, 11211, 11311, 12121, 21112, 22622, 111111, 112211, 121121, 211112, 1111111, 1112111, 1113111, 1121211, 1211121, 2111112, 2223222, 4213124, 11111111, 11122111, 11211211, 12111121, 21111112
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OFFSET

1,2


COMMENTS

Palindromes in the sequence A229550.


LINKS



EXAMPLE

77*(7*7) = 343*11 = 3773 (another palindrome). So 77 is a member of this sequence.
464*(4*6*4) = 44544 (another palindrome). So, 464 is a member of this sequence.


PROG

(Python)
def pal(n):
..r = ''
..for i in str(n):
....r = i + r
..return r == str(n)
def DP(n):
..p = 1
..for i in str(n):
....p *= int(i)
..return p
{print(n, end=', ') for n in range(1, 10**6) if DP(n)*pal(n)*pal(n*DP(n))}
(PARI) pal(n)=d=digits(n); Vecrev(d)==d
for(n=1, 10^8, d=digits(n); p=prod(i=1, #d, d[i]); if(p*pal(n)*pal(n*p), print1(n, ", "))) \\ Derek Orr, Apr 05 2015


CROSSREFS



KEYWORD

nonn,easy,base


AUTHOR



STATUS

approved



