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A239589 Numbers whose squares are cyclops numbers. 7
0, 105, 138, 145, 155, 179, 195, 205, 217, 226, 241, 243, 255, 257, 259, 274, 295, 305, 1054, 1068, 1082, 1091, 1114, 1127, 1136, 1158, 1162, 1175, 1192, 1196, 1221, 1229, 1233, 1237, 1261, 1269, 1273, 1277, 1281, 1308, 1323, 1327, 1338, 1364, 1375, 1386 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Colin Barker, Table of n, a(n) for n = 1..4000

EXAMPLE

138 is in the sequence because 138^2 = 19044, 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, 2000, if(is_cyclops(n^2), s=concat(s, n))); s

CROSSREFS

Cf. A000290, A134808, A160711, A239587, A239588, A239590, A239591.

Sequence in context: A097217 A115935 A069702 * A203614 A252069 A133509

Adjacent sequences:  A239586 A239587 A239588 * A239590 A239591 A239592

KEYWORD

nonn,base

AUTHOR

Colin Barker, Mar 24 2014

STATUS

approved

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Last modified August 19 05:06 EDT 2022. Contains 356216 sequences. (Running on oeis4.)