|
%I #4 Dec 29 2023 11:52:40
%S 1,17,94,965,841,6167,18044,225489,75220,4280111,899494,86645897,
%T 26288822,41914055,296912584,5893703327,1703822073,49486578079,
%U 14076109870,12725008135,1190932611,122366761563,203957791852
%N Numerator of Sum_{i=1..n} i^3/(n-i+1).
%C Prime p divides a(2p-1), p>3. Prime p divides a(3p-1), p>2. Prime p divides a(p-1), p>3. p^2 divides a(p^2-1) for prime p>3. p^3 divides a(p^3-1) for prime p>3. p^4 divides a(p^4-1) for prime p>3. p^5 divides a(p^5-1) for p>3.
%F a(n) = numerator( Sum_{i=1..n} i^3/(n-i+1) ).
%t Numerator[Table[Sum[i^3/(n-i+1),{i,1,n}],{n,1,50}]]
%Y Cf. A007406, A001008, A027612.
%K frac,nonn
%O 1,2
%A _Alexander Adamchuk_, Jun 25 2006
|
