Search: id:A074279 Results 1-1 of 1 results found. %I A074279 %S A074279 1,2,2,2,2,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5, %T A074279 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5 %N A074279 n appears n^2 times. %C A074279 Since the last occurrence of n comes one before the first occurrence of n+1 and the former is at SUM[i=0..n](i^2) = A000330(n), we have a(A000330(n)) = a(n*(n+1)*(2n+1)/6) = n and a(1+A000330(n)) = a(1+(n*(n+1)*(2n+1)/ 6)) = n+1. The current sequence is, loosely, the inverse function of the square pyramidal sequence. See also: A000330 Square pyramidal numbers: 0^2+1^2+2^2+...+n^2 = n(n+1)(2n+1)/6. A000330 has many alternative formulae, thus yielding many alternative formulae for the current sequence. - Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 18 2006 %H A074279 Y.-F. S. Petermann, J.-L. Remy and I. Vardi, Discrete derivatives of sequences, Adv. in Appl. Math. 27 (2001), 562-84. %Y A074279 Cf. A000217, A000330, A006331, A050446, A050447, A000537, A006003, A005900. %Y A074279 Sequence in context: A156875 A066339 A052375 this_sequence A072750 A029835 A074280 %Y A074279 Adjacent sequences: A074276 A074277 A074278 this_sequence A074280 A074281 A074282 %K A074279 nonn %O A074279 0,2 %A A074279 Jon Perry (perry(AT)globalnet.co.uk), Sep 21 2002 Search completed in 0.001 seconds