A229550 - OEIS

%I #20 Apr 15 2015 17:40:53

%S 1,2,3,11,19,22,35,37,77,111,115,116,121,131,212,464,671,731,1111,

%T 1221,1229,2112,4136,4147,6346,9832,11111,11151,11161,11211,11311,

%U 12121,12477,12692,12734,17951,18619,21112,22622

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

%H Giovanni Resta, <a href="/A229550/b229550.txt">Table of n, a(n) for n = 1..500</a>

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

%o (Python)

%o def ispal(n):

%o ..r = ''

%o ..for i in str(n):

%o ....r = i + r

%o ..return n == int(r)

%o def DP(n):

%o ..p = 1

%o ..for i in str(n):

%o ....p *= int(i)

%o ..return p

%o {print(n,end=', ') for n in range(10**4) if DP(n) and ispal(n*DP(n))}

%o ## Simplified by _Derek Orr_, Apr 10 2015

%o (PARI) ispal(n)=n=digits(n); n==Vecrev(n)

%o dprod(n)=n=digits(n); prod(i=1,#n,n[i])

%o is(n)=my(d=dprod(n)); d && ispal(d*n) \\ _Charles R Greathouse IV_, Apr 30 2014

%Y Cf. A007954.

%K nonn,base

%O 1,2

%A _Derek Orr_, Sep 26 2013