Yes, it was stated as 1 to N. But it happens that 0 to N has the same result and the formula works either way. - Dennis (The usual proof is a little different, so instead of N terms all of which total N+1, the numerator represents N+1 terms all of which total N.) -----Original Message----- From: Dale Erwin [mailto:dale@casaerwin.org] Sent: Friday, June 21, 2013 02:01 PM To: users@openoffice.apache.org Subject: Re: Calc: Easy way to do N+(N-1)+(N-2)+(N-3)..(N-N+1) I don't think that n can be zero. Dale Erwin Jr. 28 de Julio 657, Depto. 03 Magdalena del Mar, Lima 17 PERU http://leather.casaerwin.org On 6/21/2013 1:37 PM, Brian Barker wrote: > At 18:27 21/06/2013 +0000, Jonathon 'Toki' Kantoor wrote: >> Is there a formula, extension, or something in calc that enables one >> to calculate the sum of 1..N, where N is an integer between 0 and 100 >> 000 000? > > Yes. Sigma (1 to n) is n(n+1)/2. > >> If so, what is the formula, extension, or something? > > =Xn*(Xn+1)/2 > > I trust this helps. > > Brian Barker --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@openoffice.apache.org For additional commands, e-mail: users-help@openoffice.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@openoffice.apache.org For additional commands, e-mail: users-help@openoffice.apache.org