|
%I #9 Sep 17 2023 10:12:59
%S 3,120,528,139128,160554240,812293020528,379188080252621270252095320,
%T 2816640597719456759751165488439681098364673273236637971046370174350128
%N Triangular numbers of the form p^2 - 1 where p is a prime.
%e 139128 is both 527*528/2 and 373^2 - 1 (and 373 is prime).
%t Select[Prime[Range[100000]]^2-1,OddQ[Sqrt[8#+1]]&] (* The program generates the first six terms of the sequence. *) (* _Harvey P. Dale_, Sep 17 2023 *)
%Y Subsequence of A006454 and of A225115.
%K nonn
%O 1,1
%A _Shreevatsa R_, Jul 12 2013
%E a(7)-a(8) from _Giovanni Resta_, Jul 13 2013
| 