Definition:Centered Hexagonal Number/Sequence

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Definition

The sequence of centered hexagonal numbers, for $n \in \Z_{> 0}$, begins:

$1, 7, 19, 37, 61, 91, 127, 169, 217, 271, 331, 397, 469, 547, 631, 721, 817, 919, \ldots$

This sequence is A003215 in the On-Line Encyclopedia of Integer Sequences (N. J. A. Sloane (Ed.), 2008).