login
A239591
Numbers whose fourth powers are cyclops numbers.
6
0, 53, 55, 158, 177, 363, 371, 412, 429, 442, 463, 547, 556, 1092, 1116, 1148, 1409, 1478, 1516, 1527, 1612, 1622, 1633, 1692, 1694, 1724, 1738, 1754, 3262, 3263, 3276, 3283, 3338, 3362, 3366, 3402, 3436, 3464, 3468, 3473, 3512, 3538, 3631, 3723, 3724, 3833
OFFSET
1,2
LINKS
EXAMPLE
158 is in the sequence because 158^4 = 623201296, which is a cyclops number.
PROG
(PARI)
is_cyclops(k) = {
if(k==0, return(1));
my(d=digits(k), j);
if(#d%2==0 || d[#d\2+1]!=0, return(0));
for(j=1, #d\2, if(d[j]==0, return(0)));
for(j=#d\2+2, #d, if(d[j]==0, return(0)));
return(1)}
s=[]; for(n=0, 5000, if(is_cyclops(n^4), s=concat(s, n))); s
KEYWORD
nonn,base
AUTHOR
Colin Barker, Mar 24 2014
STATUS
approved