cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A287207 Numbers k such that k![6] + 2 is prime, where k![6] = A085158(k) = sextuple factorial.

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%I A287207 #7 Apr 03 2023 10:36:13
%S A287207 0,1,3,5,9,17,27,45,51,53,93,197,213,221,245,279,845,927,2055,2895,
%T A287207 3615,5613,12753,15737,17813,18545,22629,47859,48797
%N A287207 Numbers k such that k![6] + 2 is prime, where k![6] = A085158(k) = sextuple factorial.
%C A287207 a(30) > 50000.
%C A287207 The first 7 primes associated with this sequence: 3, 3, 5, 7, 29, 937, 229637.
%H A287207 C. Caldwell and H. Dubner (Eds): <a href="https://t5k.org/lists/top_ten/">The top ten prime numbers: from the unpublished collections of R. Ondrejka</a> (May 2001), Table 21 F, p. 75
%H A287207 Ken Davis, <a href="http://mfprimes.free-dc.org">Status of Search for Multifactorial Primes</a>.
%t A287207 MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
%t A287207 Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 6] + 2] &]
%t A287207 Select[Range[0,10000],PrimeQ[Times@@Range[#,1,-6]+2]&] (* The program generates the first 22 terms of the sequence. *) (* _Harvey P. Dale_, Dec 27 2022 *)
%Y A287207 Cf. A076185, A085158, A094144, A204657.
%K A287207 nonn
%O A287207 1,3
%A A287207 _Robert Price_, May 21 2017