A284742 Centered Platonic numbers.

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

Table of n, a(n) for n=1..61.

OEIS Wiki, Centered Platonic numbers [Unapproved page]

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

Cf. A001845, A005894, A005898, A005902, A005904, A053012.

Sequence in context: A048974 A089193 A302482 * A111083 A050550 A079523

Adjacent sequences: A284739 A284740 A284741 * A284743 A284744 A284745

Keyword

nonn,easy

Author

Ilya Gutkovskiy, Apr 01 2017

Status

approved