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A063272
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Number of times most common final digit of primes appears in first n primes.
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3
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1, 1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 5, 5, 5, 5, 5, 6, 6, 7, 7, 7, 7, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 10, 10, 11, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 16, 17, 17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 21, 21, 21, 21, 21, 21
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OFFSET
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1,6
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LINKS
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FORMULA
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a(n) ~ n/phi(10) = n/4 by the Prime Number Theorem in Arithmetic Progressions. - Charles R Greathouse IV, Dec 29 2012
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EXAMPLE
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a(6)=2 since first six primes are 2,3,5,7,11,13, so most common final digit is 3 which has appeared twice.
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MAPLE
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V:= Vector(9):
p:= 1:
for n from 1 to 100 do
p:= nextprime(p);
r:= p mod 10;
V[r]:= V[r]+1;
A[n]:= max(V)
od:
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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