A390630 Decimal expansion of the smallest dihedral angle, in radians, in a sphenomegacorona (Johnson solid J_88).

1, 2, 7, 3, 6, 1, 9, 0, 3, 9, 6, 8, 7, 8, 4, 1, 0, 0, 2, 5, 7, 6, 9, 4, 6, 4, 5, 5, 1, 7, 3, 9, 1, 2, 9, 4, 8, 5, 0, 9, 5, 5, 2, 0, 9, 2, 5, 8, 3, 8, 0, 4, 2, 3, 9, 3, 4, 2, 4, 8, 8, 1, 9, 9, 4, 9, 9, 2, 3, 7, 5, 1, 6, 9, 4, 6, 3, 8, 3, 2, 8, 6, 5, 2, 4, 1, 0, 6, 1, 6

Offset

1,2

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

Polytope Wiki, Sphenomegacorona.

Wikipedia, Sphenomegacorona.

Formula

Equals arccos(c), where c = 0.29282... is the smallest positive real root of 11025*x^16 + 101040*x^15 + 41416*x^14 - 622960*x^13 - 172996*x^12 + 1002032*x^11 + 480632*x^10 - 551152*x^9 - 348154*x^8 + 138128*x^7 + 114552*x^6 - 23504*x^5 - 31492*x^4 - 5232*x^3 + 1480*x^2 + 560*x + 49.

Example

1.2736190396878410025769464551739129485095520925838...

Mathematica

First[RealDigits[ArcCos[Root[11025*#^16 + 101040*#^15 + 41416*#^14 - 622960*#^13 - 172996*#^12 + 1002032*#^11 + 480632*#^10 - 551152*#^9 - 348154*#^8 + 138128*#^7 + 114552*#^6 - 23504*#^5 - 31492*#^4 - 5232*#^3 + 1480*#^2 + 560*# + 49 &, 7]], 10, 100]] (* or *)
First[RealDigits[Min[PolyhedronData["J88", "DihedralAngles"]], 10, 100]]

Crossrefs

Cf. other J_88 dihedral angles: A390631, A390632, A390633, A390634, A390635, A390636, A390637, A390638.

Cf. A334114 (J_88 volume), A010502 (J_88 surface area - 2).

Sequence in context: A082737 A334971 A387004 * A104957 A329333 A387058

Adjacent sequences: A390627 A390628 A390629 * A390631 A390632 A390633

Keyword

nonn,cons,easy

Author

Paolo Xausa, Nov 19 2025

Status

approved