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A172142 Primes of form p^q+q^p+1, where p, q are also primes. 1
2531, 94933, 48989177, 19088056323407827075424486287615602692671561637, 10027860709531471276608129899567499096303854889970269316268113271, 88537996291958256446260440678593208943077817551131498658191653913030830300434060998128240895267 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..6.

EXAMPLE

a(1)=3^7+7^3+1=2531 a(2)=5^7+7^5+1=94933 a(3)=5^11+11^5+1=48989177 a(4)=3^97+97^3+1=19088056323407827075424486287615602692671561637 a(5)=23^47+47^23+1

MATHEMATICA

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

Union[Select[First[#]^Last[#]+Last[#]^First[#]+1&/@Tuples[Prime[Range[50]], 2], PrimeQ]] (* Harvey P. Dale, Oct 17 2014 &)

CROSSREFS

Cf. A118097

Sequence in context: A268332 A203440 A231968 * A206596 A334932 A254021

Adjacent sequences:  A172139 A172140 A172141 * A172143 A172144 A172145

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified December 2 19:48 EST 2021. Contains 349445 sequences. (Running on oeis4.)