login
Numbers whose cubes are cyclops numbers.
6

%I #12 Jun 25 2022 11:59:30

%S 0,42,115,116,123,135,163,164,199,498,525,557,562,564,576,579,596,615,

%T 623,642,661,666,695,697,717,721,724,748,788,806,827,886,945,961,994,

%U 2272,2274,2319,2325,2329,2391,2438,2512,2529,2537,2545,2617,2637,2654

%N Numbers whose cubes are cyclops numbers.

%H Colin Barker, <a href="/A239590/b239590.txt">Table of n, a(n) for n = 1..1500</a>

%e 123 is in the sequence because 123^3 = 1860867, which is a cyclops number.

%o (PARI)

%o is_cyclops(k) = {

%o if(k==0, return(1));

%o my(d=digits(k), j);

%o if(#d%2==0 || d[#d\2+1]!=0, return(0));

%o for(j=1, #d\2, if(d[j]==0, return(0)));

%o for(j=#d\2+2, #d, if(d[j]==0, return(0)));

%o return(1)}

%o s=[]; for(n=0, 3000, if(is_cyclops(n^3), s=concat(s, n))); s

%Y Cf. A000578, A134808, A160711, A239587, A239588, A239589, A239591.

%K nonn,base

%O 1,2

%A _Colin Barker_, Mar 24 2014