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Search: id:A089201
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| A089201 |
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Primes p such that p-3 and p+3 are divisible by a cube. |
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+0
2
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| 683, 1747, 2659, 3253, 4253, 4397, 7253, 7549, 8747, 9829, 10253, 12253, 13037, 14747, 16253, 16747, 17747, 18253, 18637, 19891, 20747, 21269, 23747, 25253, 25747, 27253, 28123, 29501, 30253, 31253, 34253, 34603, 34747, 35747, 37253
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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683-3=2^3*5*17,683+3=2*7^3.
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PROGRAM
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(PARI) powerfreep4(n, p, k) = { c=0; pc=0; forprime(x=2, n, pc++; if(!ispowerfree(x-k, p) && !ispowerfree(x+k, p), c++; print1(x", "); ) ); print(); print(c", "pc", "c/pc+.0) } ispowerfree(m, p1) = { flag=1; y=component(factor(m), 2); for(i=1, length(y), if(y[i] >= p1, flag=0; break); ); return(flag) }
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CROSSREFS
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Sequence in context: A043763 A145321 A045154 this_sequence A065123 A076574 A015386
Adjacent sequences: A089198 A089199 A089200 this_sequence A089202 A089203 A089204
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KEYWORD
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easy,nonn
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AUTHOR
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Cino Hilliard (hillcino368(AT)gmail.com), Dec 08 2003
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