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.

A049432 Numbers k such that k! - (k-1)! + 1 is prime.

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%I A049432 #16 Jun 12 2025 03:38:22
%S A049432 2,3,4,5,6,8,13,20,24,46,59,150,152,198,683,880,1135,1907,6617,10243,
%T A049432 12016
%N A049432 Numbers k such that k! - (k-1)! + 1 is prime.
%C A049432 a(21) > 12000. [From _Donovan Johnson_, Dec 18 2009]
%H A049432 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>
%F A049432 a(n) = A090703(n) + 1. - _Michael S. Branicky_, Jun 11 2025
%e A049432 6! - (6-1)! + 1 = 601 is prime.
%Y A049432 Cf. A049984, A049433, A090703.
%K A049432 nonn
%O A049432 1,1
%A A049432 Paul Jobling (paul.jobling(AT)whitecross.com)
%E A049432 a(15)-a(16) from _Farideh Firoozbakht_, Jul 18 2003
%E A049432 a(17)-a(20) from _Donovan Johnson_, Dec 18 2009
%E A049432 a(21) from _Michael S. Branicky_, Jun 11 2025