A373642 Decimal expansion of Sum_{k>=1} (sin(Pi/k))^(2k).

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

Offset

1,2

Links

Table of n, a(n) for n=1..93.

Lewis Trem, Infinite sum of ..., Math StackExchange, Jul 8 2020.

Example

0^2 + 1^4 + (0.86602...)^6 + (0.70710..)^8 + (0.58778..)^10 + ... = 1.4895502488138264685841...

Prog

(PARI) sumpos(k = 1, sin(Pi/k)^(2*k)) \\ Amiram Eldar, Aug 20 2024

Crossrefs

Cf. A269611, A010527 (sin Pi/3), A010503 (sin Pi/4), A019845 (sin Pi/5).

Sequence in context: A117181 A328906 A194623 * A366022 A316251 A108616

Adjacent sequences: A373639 A373640 A373641 * A373643 A373644 A373645

Keyword

nonn,cons

Author

R. J. Mathar, Jun 12 2024

Status

approved