16 Jan
2020
16 Jan
'20
8:03 p.m.
JB: "The 121st of the pendulum numbers ... is a 255-digit prime..." HH: "There's one more in the first ten thousand: @ 4489 digits, the 1399th." NJAS: "Can you do a similar thing for ... A281254?" The third prime in A053063 is a(40714) with 192464 decimal digits. It wasn't until I determined this that I realized (because I had already calculated the first prime in A281254) that the even-indexed terms of A281254 duplicated the even-indexed terms of A053063. The odd-indexed terms of A281254 are divisible by two so, necessarily, the primes in A281254 are a subset of the primes in A053063, specifically those that appear at even indices.