A172146 Primes of form x^y + y^x + 1

3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 101, 2531, 4241, 5393, 94933, 262469, 16797953, 48989177, 78371693633, 2552470327703, 4747732369319, 17832200896513, 131621703955647041, 4052555153019035587

Offset

1,1

Links

Table of n, a(n) for n=1..28.

Example

a(1)=1^1+1^1+1=3 a(2)=1^3+3^1+1=5 a(3)=1^5+5^1+1=7 ... a(15)=2^6+6^2+1=101

Mathematica

a[n_] := Block[{}, For[l = {}; i = 1, i < n, i++, For[j = i, j < n, j++, x = i^j + j^i + 1; If[PrimeQ[x], l = Append[l, x]]]]; Print[Sort[Union[l]]]]; a[50]

Crossrefs

Cf. A094133, A172142

Sequence in context: A191376 A179429 A020615 * A225670 A165255 A223036

Adjacent sequences: A172143 A172144 A172145 * A172147 A172148 A172149

Keyword

nonn

Author

Cheng Zhang (cz1(AT)rice.edu), Jan 26 2010, Mar 03 2010

Status

approved