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Search: id:A161747
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| A161747 |
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Distinct primes that are the difference between a fifth and a fourth power. |
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+0
1
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| 31, 227, 1051, 3109, 7151, 15511, 18127, 30367, 32143, 32687, 144719, 151051, 165311, 186343, 234191, 302399, 369997, 371281, 374239, 407503, 454303, 509263, 531263, 537743, 759359, 1053007, 1088081, 1182287, 1185601, 1354321, 1381441
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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If x^5-y^4 is prime for integers x,y list without duplicates.
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EXAMPLE
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2^5 - 1^4 = 31.
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PROGRAM
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(PARI) diffpowers(n, m) =
{
local(a, c=0, c2=0, j, k, y);
a=vector(floor(n^2/log(n^2)));
for(j=1, n,
for(k=1, n,
y=j^m-k^(m-1);
if(ispseudoprime(y),
c++;
\\ print(j", "k", "y);
a[c]=y;
);
);
);
a=vecsort(a);
for(j=2, length(a),
if(a[j]!=a[j-1]&&a[j]!=0,
c2++;
print1(a[j]", ");
if(c2>100, break);
);
);
}
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CROSSREFS
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Sequence in context: A075931 A142440 A075932 this_sequence A059899 A140846 A082544
Adjacent sequences: A161744 A161745 A161746 this_sequence A161748 A161749 A161750
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KEYWORD
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nonn,uned
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AUTHOR
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Cino Hilliard (hillcino368(AT)hotmail.com), Jun 17 2009
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