A239588 Fourth powers that are cyclops numbers.

0, 7890481, 9150625, 623201296, 981506241, 17363069361, 18945044881, 28813025536, 33871089681, 38167092496, 45954068161, 89526025681, 95565066496, 1421970391296, 1551160647936, 1736870953216, 3941340648961, 4771970346256, 5281980641536, 5436960129441

Offset

1,2

Comments

Intersection of A000583 (Fourth powers) and A134808 (Cyclops numbers).

Links

Colin Barker, Table of n, a(n) for n = 1..1500

Formula

a(n) = A239591(n)^4.

Mathematica

cn4Q[n_]:=Module[{idn=IntegerDigits[n], len}, len=Length[idn]; OddQ[ len] && idn[[(len+1)/2]]==0&&DigitCount[n, 10, 0]==1]; Select[Range[0, 2000]^4, cn4Q] (* Harvey P. Dale, Dec 20 2015 *)

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, 2000, if(is_cyclops(n^4), s=concat(s, n^4))); s

Crossrefs

Cf. A000583, A134808, A160711, A239587, A239589, A239590, A239591.

Sequence in context: A206186 A205368 A235222 * A210275 A346029 A237338

Adjacent sequences: A239585 A239586 A239587 * A239589 A239590 A239591

Keyword

nonn,base

Author

Colin Barker, Mar 24 2014

Status

approved