|
%I #11 Feb 17 2023 07:40:11
%S 2,5,5,7,7,7,5,11,11,13,13,13,7,17,17,19,19,19,11,23,23,23,13,13,13,
%T 29,29,31,31,31,17,17,17,37,37,37,19,41,41,43,43,43,23,47,47,47,7,17,
%U 17,53,53,53,11,19,29,59,59,61,61,61,31,13,13,67,67,67,23,71,71,73,73,73,37
%N Greatest prime factor of pyramidal number A000292(n).
%C a(n) <= n+2, with equality if n+2 is prime. - _Robert Israel_, Feb 16 2023
%H Robert Israel, <a href="/A121359/b121359.txt">Table of n, a(n) for n = 2..10000</a>
%F a(n) = A006530(A000292(n)).
%p f:= n -> max(numtheory:-factorset(n*(n+1)*(n+2)/6)):
%p map(f, [$2..100]); # _Robert Israel_, Feb 16 2023
%t FactorInteger[#][[-1,1]]&/@Binomial[Range[2,80]+2,3] (* _Harvey P. Dale_, Jan 31 2013 *)
%Y Cf. A000292, A006530.
%K nonn
%O 2,1
%A _Zak Seidov_, Sep 06 2006
%E Offset corrected by _Robert Israel_, Feb 16 2023
|
