Thread: Consecutive integers...

The sum of c consecutive positive integers = c^2.
Example, c=5: 3+4+5+6+7 = 25 ; 5^2 = 25
(last integer = 7)

If c = 9999, what is the last integer?

What is the last integer in terms of c?

Code:

c:=9999:
for n from 1 to 10000 do
if sum(k,k=n..n+c-1)=c^2 then
print(n+c-1);
break;
end if;
end do;

for , last integer =

in terms of , last integer =

Good one Princeps.
Accidentally got that while fooling around with consecutive numbers.
Had you seen the "easy formula" last integer = (3c - 1)/2 before?
Amazing that there is a solution for ALL odd c's.