A figurate number which is equal to the cubic number 
.
The first few are 1, 8, 27, 64, ... (OEIS A000578).
Hex Pyramidal Number
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References
Conway, J. H. and Guy, R. K. The Book of Numbers. New York: Springer-Verlag, pp. 42-44, 1996.Sloane, N. J. A. Sequence A000578/M4499 in "The On-Line Encyclopedia of Integer Sequences."Referenced on Wolfram|Alpha
Hex Pyramidal NumberCite this as:
Weisstein, Eric W. "Hex Pyramidal Number." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/HexPyramidalNumber.html