Square pyramidal number: Revision history

18 December 2014

• curprev 01:3801:38, 18 December 2014‎ en>David Eppstein‎ m 10,632 bytes +109‎ authorlink Jesús A. De Loera

4 February 2014

• curprev 17:3617:36, 4 February 2014‎ en>TakuyaMurata‎ m 10,523 bytes −16‎ →‎Formula

31 December 2013

• curprev 00:3400:34, 31 December 2013‎ en>Little Mountain 5‎ m 10,539 bytes +10,539‎ →‎Derivation of the summation formula: "now there"→"there are" per edit request

4 June 2012

• curprev 21:0421:04, 4 June 2012‎ en>Helder.wiki‎ 7,620 bytes +7,620‎ +ref for "\sum_{k=1}^nk^2 = \frac{n(n + 1)(2n + 1)}{6}": Hopcroft, Motwani & Ullman (2007), p. 20