cp's OEIS Frontend

A188897 a(n) = lcm(n, n+1, n+2, n+3, n+4, n+5, n+6, n+7)/840.

%I A188897 #21 Mar 31 2025 11:58:28
%S A188897 0,1,3,3,33,33,429,429,429,858,4862,14586,25194,25194,1938,21318,
%T A188897 490314,245157,72105,312455,148005,148005,4292145,390195,525915,
%U A188897 2103660,4628052,6052068,672452,2017356,2573868
%N A188897 a(n) = lcm(n, n+1, n+2, n+3, n+4, n+5, n+6, n+7)/840.
%F A188897 a(n) = (n+7)!/(5040*(n-1)!*p(n)*q(n)*(1+6*f(n))), n > 1 where
%F A188897 p(n) = 8*3^((n-1)^2 mod 3),
%F A188897 q(n) = 4*(((n-2)^4 mod 5 +(n-1)^4) mod 5)-3, and
%F A188897 f(n) = 1-(n^6 mod 7).
%p A188897 seq(lcm(n,n+1,n+2,n+3,n+4,n+5,n+6,n+7)/840, n=0..30);
%p A188897 p:=n-> 8*3^((n-1)^2 mod 3):q:=n-> 4*(((n-2)^4 mod 5 +(n-1)^4)mod5)-3:f:=n-> 1-(n^6 mod 7): seq((n+7)!/(5040*(n-1)!*p(n)*q(n)*(1+6*f(n))),n=1..30)
%Y A188897 Cf. A189144.
%K A188897 nonn
%O A188897 0,3
%A A188897 _Gary Detlefs_, Apr 19 2011
%E A188897 Missing term a(5)=33 inserted by _Georg Fischer_, Mar 31 2025