A239591 Numbers whose fourth powers are cyclops numbers.

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

Colin Barker, Table of n, a(n) for n = 1..1000

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

Crossrefs

Cf. A000583, A134808, A160711, A239587, A239588, A239589, A239590.

Sequence in context: A343794 A042403 A217609 * A344797 A344798 A294739

Adjacent sequences: A239588 A239589 A239590 * A239592 A239593 A239594

Keyword

nonn,base

Author

Colin Barker, Mar 24 2014

Status

approved