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a(n) = n-th prime modulo 30.
3

%I #14 Dec 13 2024 10:24:15

%S 2,3,5,7,11,13,17,19,23,29,1,7,11,13,17,23,29,1,7,11,13,19,23,29,7,11,

%T 13,17,19,23,7,11,17,19,29,1,7,13,17,23,29,1,11,13,17,19,1,13,17,19,

%U 23,29,1,11,17,23,29,1,7,11,13,23,7,11,13,17,1,7,17,19,23,29,7,13,19

%N a(n) = n-th prime modulo 30.

%C A002110(3) = 2*3*5 = 30; range for n>3: {1,7,11,13,17,19,23,29} of size 8 = A000720(30) - #{2,3,5} + #{1} = 10 - 3 + 1 = A000010(30).

%H Vincenzo Librandi, <a href="/A095959/b095959.txt">Table of n, a(n) for n = 1..1000</a>

%F Sum_k={1..n} a(k) ~ 15*n. - _Amiram Eldar_, Dec 13 2024

%t Mod[Prime[Range[80]], 30] (* _Harvey P. Dale_, Jul 21 2013 *)

%o (Magma) [p mod(30): p in PrimesUpTo(500)]; // _Vincenzo Librandi_, May 07 2014

%Y Cf. similar sequences listed in A242119.

%Y Cf. A000010, A000720, A002110.

%K nonn,easy

%O 1,1

%A _Reinhard Zumkeller_, Jul 14 2004