Heptagonal numbers(redirected from Heptagonal number)
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Related to Heptagonal number: Pentagonal number
|(Arith.)||the numbers of the series 1, 7, 18, 34, 55, etc., being figurate numbers formed by adding successively the terms of the arithmetical series 1, 6, 11, 16, 21, etc.|
See also: Heptagonal