A013605 - OEIS

%I #15 Aug 14 2019 08:35:27

%S 2,2,12,6,4,6,4,44,16,6,12,12,52,2,4,62,16,102,16,26,54,54,36,38,64,2,

%T 12,42,16,102,18,72,42,68,256,18,52,84,234,54,34,72,274,266,36,14,4,

%U 56,162,2,24,122,6,14,94,446,72,56,298,384,28,26

%N a(n) = 5^n-prevprime(5^n).

%H Daniel Starodubtsev, <a href="/A013605/b013605.txt">Table of n, a(n) for n = 1..1000</a>

%p seq(5^i-prevprime(5^i),i=1..100);

%t #-NextPrime[#,-1]&/@(5^Range[70])  (* _Harvey P. Dale_, Mar 12 2011 *)

%o (PARI) a(n) = 5^n - precprime(5^n-1); \\ _Michel Marcus_, Aug 14 2019

%Y Cf. A000351, A104090.

%K nonn

%O 1,1

%A James Kilfiger (mapdn(AT)csv.warwick.ac.uk)