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A248644
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Evil numbers (A001969) remaining evil if any digit is deleted (zeros allowed).
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3
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0, 3, 5, 6, 9, 30, 33, 36, 39, 53, 60, 63, 65, 66, 90, 95, 96, 99, 105, 120, 172, 175, 177, 178, 180, 209, 240, 243, 277, 300, 303, 306, 330, 340, 343, 360, 363, 366, 390, 396, 399, 430, 480, 483, 485, 486, 533, 534, 543, 571, 600, 603, 605, 606, 630, 633, 636, 658, 660, 663
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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COMMENTS
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Although for numbers >9 we never put 0 instead of the removed digit, we include single-digit numbers 0,3,5,6,9 since, e.g., 3=03, etc.
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LINKS
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EXAMPLE
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172 is in the sequence since 172,72,12,17 are evil.
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PROG
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(Sage)
def is_evil(n):
if n==0:
return True
else:
return sum(Integer(n).digits(base=2))%2==0
def remain_evil(n):
if not(is_evil(n)):
return False
else:
L=Integer(n).digits(base=10)
M=[]
for i in [0..len(L)-1]:
G=L[0:i]+L[i+1:]
M.append(is_evil(sum(G[i]*10^i for i in [0..len(G)-1])))
return sum(M)==len(M)
[x for x in [0..500] if remain_evil(x)] # Tom Edgar, Oct 10 2014
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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