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A284742
Centered Platonic numbers.
0
1, 5, 7, 9, 13, 15, 25, 33, 35, 55, 63, 69, 91, 121, 129, 147, 155, 189, 195, 231, 295, 309, 341, 377, 425, 427, 559, 561, 575, 589, 791, 833, 855, 909, 923, 1035, 1159, 1241, 1325, 1415, 1561, 1661, 1665, 1729, 2047, 2057, 2059, 2331, 2511, 2625, 2743, 2869, 3025, 3059, 3303, 3605, 3871, 3925, 4089, 4215, 4255
OFFSET
1,2
COMMENTS
Union of centered tetrahedral numbers (A005894), centered octahedral numbers (A001845), centered cube numbers (A005898), centered icosahedral numbers (A005902) and centered dodecahedral numbers (A005904).
LINKS
MATHEMATICA
nn = 18; t1 = Table[(2 n + 1) (n^2 + n + 3)/3, {n, 0, nn}]; t2 = Table[(2 n + 1) (2 n^2 + 2 n + 3)/3, {n, 0, nn}]; t3 = Table[n^3 + (n + 1)^3, {n, 0, nn}]; t4 = Table[(2 n + 1) (5 n^2 + 5 n + 3)/3, {n, 0, nn}]; t5 = Table[(2 n + 1) (5 n^2 + 5 n + 1), {n, 0, nn}]; Select[Union[t1, t2, t3, t4, t5], # <= t1[[-1]] &]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ilya Gutkovskiy, Apr 01 2017
STATUS
approved