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A267144
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Octagonal numbers with prime indices.
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2
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8, 21, 65, 133, 341, 481, 833, 1045, 1541, 2465, 2821, 4033, 4961, 5461, 6533, 8321, 10325, 11041, 13333, 14981, 15841, 18565, 20501, 23585, 28033, 30401, 31621, 34133, 35425, 38081, 48133, 51221, 56033, 57685, 66305, 68101, 73633, 79381, 83333, 89441, 95765
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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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MATHEMATICA
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Table[Prime[n] (3 Prime[n] - 2), {n, 1, 45}]
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PROG
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(PARI) lista(nn) = forprime(p=2, nn, print1(p*(3*p-2), ", ")); \\ Altug Alkan, Jan 11 2016
(Magma) [NthPrime(n)*(3*NthPrime(n)-2): n in [1..50]]; // Vincenzo Librandi, Jan 12 2016
(Python)
from sympy import prime
def a(n): p = prime(n); return p*(3*p-2)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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