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A067830
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Primes p such that sigma(p-4) < p.
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3
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5, 7, 11, 17, 23, 41, 47, 71, 83, 101, 107, 113, 131, 167, 197, 227, 233, 281, 311, 317, 353, 383, 401, 443, 461, 467, 491, 503, 617, 647, 677, 743, 761, 773, 827, 857, 863, 881, 887, 911, 941, 971, 1013, 1091, 1097, 1217, 1283, 1301, 1307, 1427, 1433, 1451
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OFFSET
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1,1
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COMMENTS
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Except for the first term, members are primes of the form p+4 with p prime, i.e., the sequence is essentially A031505, A046132. In other words the solutions to sigma(x) < x + 4 are 1,2,4 and the odd primes. - Ralf Stephan, Feb 09 2004
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LINKS
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Table of n, a(n) for n=1..52.
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PROG
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(PARI) isok(p) = isprime(p) && (p>4) && (sigma(p-4) < p); \\ Michel Marcus, Feb 15 2021
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CROSSREFS
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Cf. A025584, A046022.
Sequence in context: A156104 A191080 A293200 * A191019 A106862 A027690
Adjacent sequences: A067827 A067828 A067829 * A067831 A067832 A067833
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KEYWORD
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nonn,easy
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AUTHOR
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Benoit Cloitre, Feb 08 2002
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EXTENSIONS
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Edited by Charles R Greathouse IV, Mar 19 2010
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STATUS
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approved
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