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A357253 a(n) is the largest prime < 6*n.

%I A357253 #34 Jan 28 2024 03:44:22
%S A357253 5,11,17,23,29,31,41,47,53,59,61,71,73,83,89,89,101,107,113,113,113,
%T A357253 131,137,139,149,151,157,167,173,179,181,191,197,199,199,211,211,227,
%U A357253 233,239,241,251,257,263,269,271,281,283,293,293,293,311,317,317,317,331,337,347,353
%N A357253 a(n) is the largest prime < 6*n.
%C A357253 Largest prime that can be obtained after n rolls of a fair 6-sided die.
%H A357253 Noga Alon and Yaakov Malinovsky, <a href="https://arxiv.org/abs/2209.07698">Hitting a prime in 2.43 dice rolls (on average)</a>, arXiv:2209.07698 [math.PR], 2022.
%F A357253 a(n) = A007917(A008588(n)).
%F A357253 a(n) = A151799(A008588(n)), since 6*n is never prime.
%e A357253 a(11) = 61 as the largest prime <= 6*11 = 66 is 61; each of 62, 63, 64, 65 and 66 are not prime. - _David A. Corneth_, Sep 20 2022
%p A357253 a:= n-> prevprime(6*n):
%p A357253 seq(a(n), n=1..60);  # _Alois P. Heinz_, Sep 20 2022
%t A357253 a[n_] := NextPrime[6*n, -1]; Array[a, 60] (* _Amiram Eldar_, Sep 20 2022 *)
%o A357253 (PARI) a(n) = precprime(6*n);
%o A357253 (Python)
%o A357253 from sympy import prevprime
%o A357253 def A357253(n): return prevprime(6*n) # _Chai Wah Wu_, Sep 20 2022
%Y A357253 Cf. A002476, A007528, A007917, A008588, A060308, A118749, A151799.
%K A357253 nonn,easy
%O A357253 1,1
%A A357253 _Michel Marcus_, Sep 20 2022