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URL: https://oeis.org/A281794

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A281794
The largest prime factor of (1+n^2)*(1+n^3).
2
1, 2, 5, 7, 17, 13, 37, 43, 19, 73, 101, 61, 29, 157, 197, 211, 257, 29, 307, 181, 401, 421, 463, 53, 577, 601, 677, 73, 757, 421, 67, 37, 331, 151, 1123, 613, 1297, 137, 67, 1483, 1601, 547, 1723, 139, 631, 1013, 109, 103, 461, 1201, 61, 2551, 541, 919
OFFSET
0,2
LINKS
FORMULA
a(n) = max( A014442(n), A081256(n)).
a(n) = A006530(A281661(n)).
MAPLE
A281794 := proc(n)
A006530((1+n^2)*(1+n^3)) ;
end proc:
seq(A281794(n), n=0..60) ;
MATHEMATICA
Table[Max[Transpose[FactorInteger[(1 + n^2) (1 + n^3)]][[1]]], {n, 0, 60}] (* Vincenzo Librandi, Jun 03 2017 *)
PROG
(Magma) [#f eq 0 select 1 else f[ #f][1] where f is Factorization((1+n^2)*(1+n^3)): n in [0..60]]; // Vincenzo Librandi, Jun 03 2017
(PARI) a(n) = if (n==0, 1, my(f=factor((1+n^2)*(1+n^3))); vecmax(f[, 1])); \\ Michel Marcus, Jun 03 2017; corrected Jun 13 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
R. J. Mathar, Jan 30 2017
STATUS
approved