A332180
a(n) = 8*(10^(2n+1)-1)/9 - 8*10^n.
Original entry on oeis.org
0, 808, 88088, 8880888, 888808888, 88888088888, 8888880888888, 888888808888888, 88888888088888888, 8888888880888888888, 888888888808888888888, 88888888888088888888888, 8888888888880888888888888, 888888888888808888888888888, 88888888888888088888888888888, 8888888888888880888888888888888
Offset: 0
Cf.
A138148 (cyclops numbers with binary digits only),
A002113 (palindromes).
Cf.
A332120 ..
A332190 (variants with different repeated digit 2, ..., 9).
Cf.
A332181 ..
A332189 (variants with different middle digit 1, ..., 9).
Subsequence of
A006072 (numbers with mirror symmetry about middle),
A153806 (strobogrammatic cyclops numbers), and
A204095 (numbers whose decimal digits are in {0,8}).
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A332180 := n -> 8*((10^(2*n+1)-1)/9-10^n);
-
Array[8 ((10^(2 # + 1)-1)/9 - 10^#) &, 15, 0]
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apply( {A332180(n)=(10^(n*2+1)\9-10^n)*8}, [0..15])
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def A332180(n): return (10**(n*2+1)//9-10**n)*8
A332191
a(n) = 10^(2n+1) - 1 - 8*10^n.
Original entry on oeis.org
1, 919, 99199, 9991999, 999919999, 99999199999, 9999991999999, 999999919999999, 99999999199999999, 9999999991999999999, 999999999919999999999, 99999999999199999999999, 9999999999991999999999999, 999999999999919999999999999, 99999999999999199999999999999, 9999999999999991999999999999999
Offset: 0
Cf.
A138148 (cyclops numbers with binary digits only),
A002113 (palindromes).
Cf.
A332121 ..
A332181 (variants with different repeated digit 2, ..., 8).
-
A332191 := n -> 10^(n*2+1)-1-8*10^n;
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Array[ 10^(2 # + 1)-1-8*10^# &, 15, 0]
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apply( {A332191(n)=10^(n*2+1)-1-8*10^n}, [0..15])
-
def A332191(n): return 10**(n*2+1)-1-8*10^n
Showing 1-2 of 2 results.
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