|
|
A153806
|
|
Strobogrammatic cyclops numbers.
|
|
9
|
|
|
0, 101, 609, 808, 906, 11011, 16091, 18081, 19061, 61019, 66099, 68089, 69069, 81018, 86098, 88088, 89068, 91016, 96096, 98086, 99066, 1110111, 1160911, 1180811, 1190611, 1610191, 1660991, 1680891, 1690691, 1810181, 1860981
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
1680891 is a member because it is the same upside down (A000787) and also a cyclops number (A134808).
|
|
MATHEMATICA
|
Select[Range[10^7], And[OddQ@ Length@#, Part[#, Ceiling[Length[#]/2]] == 0, Times @@ Boole@ Map[MemberQ[{0, 1, 6, 8, 9}, #] &, Union@ #] == 1, Count[#, 0] == 1, (Take[#, Floor[Length[#]/2]] /. {6 -> 9, 9 -> 6}) ==
Reverse@ Take[#, -Floor[Length[#]/2]]] &@ IntegerDigits@ # &] (* Michael De Vlieger, Jul 05 2016 *)
|
|
PROG
|
(Python)
import sys
f = open('b153806.txt', 'w')
i = 1
n = 0
a = [""]
r = [""] #reversed strobogrammatically
while True:
....for x, y in zip(a, r):
........f.write(str(i)+" "+x+"0"+y+"\n")
........i += 1
........if i>20000:
............f.close()
............sys.exit()
....a = sum([[x+"1", x+"6", x+"8", x+"9"] for x in a], [])
....r = sum([["1"+x, "9"+x, "8"+x, "6"+x] for x in r], [])
|
|
CROSSREFS
|
|
|
KEYWORD
|
base,easy,nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|