|
%I #13 Oct 25 2015 17:33:31
%S 0,1,2,11,101,111,1001,10001,10101,11011,100001,101101,110011,1000001,
%T 1001001,1100011,10000001,10011001,10100101,11000011,100000001,
%U 100010001,100101001,101000101,110000011,1000000001,1000110001
%N Palindromic numbers whose squares and cubes are equally palindromic.
%C Numbers n such that n, n^2 and n^3 are all palindromes.
%C Essentially A002780 with two terms removed, 7 and 2201.
%e 11^2=121, 11^3=1331.
%p rev:=proc(a) local aa,ct: aa:=convert(a,base,10): ct:=nops(aa): add(10^(ct-j)*aa[j],j=1..ct) end: p:=proc(n) if rev(n)=n and rev(n^2)=n^2 and rev(n^3)=n^3 then n else fi end: seq(p(n),n=0..12*10^5); # _Emeric Deutsch_, May 01 2005
%o (PARI) ispal(n) = my(d = digits(n)); Vecrev(d) == d;
%o isok(n) = ispal(n) && ispal(n^2) && ispal(n^3); \\ _Michel Marcus_, Oct 25 2015
%Y Cf. A002779, A002781.
%Y Intersection of A002113, A002778 and A002780.
%K nonn,base
%O 1,3
%A _Labos Elemer_, Oct 01 2003
%E More terms from _Ray Chandler_, Oct 05 2003
%E Edited by _N. J. A. Sloane_, Aug 29 2008 at the suggestion of _R. J. Mathar_
|
