A136292 Primes of the form a^a + b^b + c^c + d^d + e^e.

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

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Formula

A000040 INTERSECTION {A000312(a) + A000312(b) + A000312(c) + A000312(d) + A000312(e)}.

Example

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.

Mathematica

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]

Prog

(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

Crossrefs

Cf. A000040, A000312, A068145, A133664.

Sequence in context: A231652 A321792 A068072 * A088046 A155882 A087373

Adjacent sequences: A136289 A136290 A136291 * A136293 A136294 A136295

Keyword

easy,nonn

Author

Jonathan Vos Post, Apr 11 2008

Status

approved