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A053609
Primes of form x^2+1 where x = LCM(1,2,...,k) for some k.
1
2, 5, 37, 176401, 129859329601, 516625648014869290354797521879383114125823989794742396526049715541246671360001
(list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The next term has k > 10^4, if it exists. - Amiram Eldar, Aug 23 2024
LINKS
Table of n, a(n) for n=1..6.
FORMULA
a(n) = A053608(A053608(n)) = A053608(n)^2 + 1. - Amiram Eldar, Aug 23 2024
MATHEMATICA
Select[FoldList[LCM, 1, Select[Range[100], PrimePowerQ]]^2 + 1, PrimeQ] (* Amiram Eldar, Aug 23 2024 *)
CROSSREFS
Cf. A049536, A046029, A051739, A051418, A051451, A053608.
Sequence in context: A222318 A084436 A210482 * A036780 A051501 A221681
Adjacent sequences: A053606 A053607 A053608 * A053610 A053611 A053612
KEYWORD
nonn,hard
AUTHOR
Labos Elemer, Feb 09 2000
STATUS
approved

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Last modified September 28 05:35 EDT 2024. Contains 376274 sequences.
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