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A227064
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Primes prime(k) such that the gap prime(k-1) - prime(k-2) equals the gap prime(k+2) - prime(k+1).
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2
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7, 23, 37, 59, 67, 71, 73, 89, 163, 167, 233, 241, 269, 277, 367, 379, 389, 449, 479, 557, 569, 587, 599, 601, 631, 743, 751, 757, 809, 967, 983, 1009, 1033, 1039, 1109, 1117, 1229, 1283, 1297, 1307, 1361, 1439, 1523, 1559, 1607, 1609, 1613, 1637, 1669
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OFFSET
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1,1
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COMMENTS
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This rephrases patterns of the form g, *, *, g in four successive entries of A001223, where * denotes arbitrary, not necessarily distinct, values.
The associated indices are n = 4, 9, 12, 17, 19, 20, 21, 24, 38, ...
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LINKS
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FORMULA
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EXAMPLE
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7 is in the sequence since the gap between the previous two primes (3 and 5) is equal to the gap between the next two primes (11 and 13).
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PROG
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(Python) from sympy import sieve as p
print([p[k] for k in range(3, 264) if p[k-1] - p[k-2] == p[k+2] - p[k+1]])
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CROSSREFS
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KEYWORD
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nonn,less
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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