On tetrahedral numbers.
Bollettino della Unione matematica italiana, Série 3, Tome 17 (1962) no. 4, p. 357
@article{BUMI_1962_3_17_4_a1,
author = {Simpson, Harold},
title = {On tetrahedral numbers.},
journal = {Bollettino della Unione matematica italiana},
pages = {357--357},
year = {1962},
volume = {Ser. 3, 17},
number = {4},
zbl = {0108.26703},
mrnumber = {146140},
language = {en},
url = {http://geodesic.mathdoc.fr/item/BUMI_1962_3_17_4_a1/}
}
Simpson, Harold. On tetrahedral numbers.. Bollettino della Unione matematica italiana, Série 3, Tome 17 (1962) no. 4, p. 357. http://geodesic.mathdoc.fr/item/BUMI_1962_3_17_4_a1/