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A136292
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Primes of the form a^a + b^b + c^c + d^d + e^e.
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2
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5, 11, 17, 31, 37, 43, 83, 89, 109, 263, 269, 521, 541, 547, 593, 773, 1051, 3181, 3187, 3413, 3691, 6763, 9377, 9403, 9887, 12527, 46663, 46993, 49787, 50549, 52937, 53189, 93851, 96697, 99563, 139999, 823547, 823553, 823573, 823651, 823831
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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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EXAMPLE
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a(1) = 5 = 1^1 + 1^1 + 1^1 + 1^1 + 1^1.
a(2) = 11 = 1^1 + 1^1 + 1^1 + 2^2 + 2^2.
a(3) = 17 = 1^1 + 2^2 + 2^2 + 2^2 + 2^2.
a(4) = 31 = 1^1 + 1^1 + 1^1 + 1^1 + 3^3.
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MATHEMATICA
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Select[Union[ Flatten[Table[ a^a + b^b + c^c + d^d + e^e, {a, 1, 20}, {b, 1, a}, {c, 1, b}, {d, 1, c}, {e, 1, d}]]], PrimeQ]
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PROG
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(PARI) v=[]; for(a=1, 50, for(b=1, a, for(c=1, b, for(d=1, c, for(e=1, d, if(ispseudoprime(t=a^a+b^b+c^c+d^d+e^e), v=concat(v, t))))))); v \\ Charles R Greathouse IV, Feb 15 2011
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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