[seqfan] Like A6919, but starting with 20

Alonso Del Arte alonso.delarte at gmail.com
Fri Oct 7 16:18:58 CEST 2022


 The 13th term of A6919 is a prime number, thereby reaching a fixed point.
I've played around with similar sequences with different starting points.
Most of the ones I've looked at quickly reach a prime. But the one starting
with 20, if my calculations are correct, goes like this

20, 225, 3355, 51161, 114651, 3312739, 17194867, 194122073, 709273797,
39713717791, 113610337981, 733914786213, 3333723311815403,
131723655857429041, 772688237874641409, 3318308475676071413

I do believe this one too reaches a prime eventually. Can someone verify
what I've got so far?

Al



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