de Bruijn, N. G. Some classes of integer-valued functions. (English) Zbl 0067.27301 Nederl. Akad. Wet., Proc. Ser. A 58, 363-367 (1955). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 2 ReviewsCited in 4 Documents Keywords:number theory PDFBibTeX XMLCite \textit{N. G. de Bruijn}, Nederl. Akad. Wet., Proc., Ser. A 58, 363--367 (1955; Zbl 0067.27301) Online Encyclopedia of Integer Sequences: a(n) = n^2*(n^2 + 1)/2.