A229550 Numbers n with nonzero digits such that n*(product of digits of n) is a palindrome.

1, 2, 3, 11, 19, 22, 35, 37, 77, 111, 115, 116, 121, 131, 212, 464, 671, 731, 1111, 1221, 1229, 2112, 4136, 4147, 6346, 9832, 11111, 11151, 11161, 11211, 11311, 12121, 12477, 12692, 12734, 17951, 18619, 21112, 22622

Offset

1,2

Links

Giovanni Resta, Table of n, a(n) for n = 1..500

Example

4136*(4*1*3*6) = 297792 (a palindrome). So, 4136 is a member of this sequence.

Prog

(Python)
def ispal(n):
..r = ''
..for i in str(n):
....r = i + r
..return n == int(r)
def DP(n):
..p = 1
..for i in str(n):
....p *= int(i)
..return p
{print(n, end=', ') for n in range(10**4) if DP(n) and ispal(n*DP(n))}
## Simplified by Derek Orr, Apr 10 2015
(PARI) ispal(n)=n=digits(n); n==Vecrev(n)
dprod(n)=n=digits(n); prod(i=1, #n, n[i])
is(n)=my(d=dprod(n)); d && ispal(d*n) \\ Charles R Greathouse IV, Apr 30 2014

Crossrefs

Cf. A007954.

Sequence in context: A257979 A365374 A095984 * A172258 A306395 A363497

Adjacent sequences: A229547 A229548 A229549 * A229551 A229552 A229553

Keyword

nonn,base

Author

Derek Orr, Sep 26 2013

Status

approved