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Primes of the form 5^k + 5*k + 1.
1

%I #13 Dec 03 2018 12:47:09

%S 2,11,48828181,298023223876953251,2910383045673370361328301,

%T 258493941422821148397315216271863391739316284656524658203551

%N Primes of the form 5^k + 5*k + 1.

%C The next term is too large to include.

%C The next term has 349 digits. - _Harvey P. Dale_, Dec 03 2018

%F a(n) = 5^A301635(n) + 5*A301635(n) + 1.

%t Select[Table[5^n+5n+1,{n,0,550}],PrimeQ] (* _Harvey P. Dale_, Dec 03 2018 *)

%Y Primes of the form b^k+b*k+1: A163115 (b=2), A180269 (b=3), this sequence (b=5).

%Y Cf. A301635.

%K nonn

%O 1,1

%A _Seiichi Manyama_, Mar 25 2018