login
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
OFFSET
1,2
COMMENTS
Intersection of A000787 and A134808.
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], [])
# Kenny Lau, Jul 05 2016
KEYWORD
base,easy,nonn
AUTHOR
Omar E. Pol, Jan 15 2009
EXTENSIONS
Extended beyond 11011 by R. J. Mathar, Jan 17 2009
STATUS
approved