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A363477
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Numbers that are integer averages of first k odd primes for some k.
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2
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3, 4, 5, 133, 169, 1117, 2406, 3564, 6141, 7429, 8220, 8475, 14193, 33543, 121049, 211785, 877650, 5948070, 8494543, 27820975, 41428418, 130490020, 139053727, 200325407, 291720414, 893706168, 977748014, 2103851425, 2173904606, 5996888467, 15790305181
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = Sum_{i=1..A097961(n)} prime(i)/n.
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EXAMPLE
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5 is a term because 5 is the average of the first 3 odd primes, 3, 5 and 7.
133 is a term because 133 is the average of the first 60 odd primes, 3, 5, 7, 11, ..., 281 and 283.
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PROG
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(Python)
from sympy import sieve
L = sieve.primerange(3, 4*10**10); s, k = 0, 0
for p in L:
s += p; k += 1
if s%k == 0: print(s//k, end = ", ")
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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