A centered pentagonal number is a centered figurate number that represents a pentagon with a dot in the center and all other dots surrounding the center in successive pentagonal layers. The centered pentagonal number for n is given by the formula
The first few centered pentagonal numbers are
1, 6, 16, 31, 51, 76, 106, 141, 181, 226, 276, 331, 391, 456, 526, 601, 681, 766, 856, 951, 1051, 1156, 1266, 1381, 1501, 1626, 1756, 1891, 2031, 2176, 2326, 2481, 2641, 2806, 2976 (sequence A005891 in OEIS).
The parity of centered pentagonal numbers follows the pattern even-even-odd-odd, and in base 10 the units follow the pattern 6-6-1-1.
Famous quotes containing the words centered and/or number:
“The difference between style and taste is never easy to define, but style tends to be centered on the social, and taste upon the individual. Style then works along axes of similarity to identify group membership, to relate to the social order; taste works within style to differentiate and construct the individual. Style speaks about social factors such as class, age, and other more flexible, less definable social formations; taste talks of the individual inflection of the social.”
—John Fiske (b. 1939)
“The quality of moral behaviour varies in inverse ratio to the number of human beings involved.”
—Aldous Huxley (1894–1963)