A395755 - OEIS

A395755

Decimal expansion of the sum of the reciprocals of octagonal polygorials A084941.

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

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OFFSET

1,1

LINKS

Kelvin Voskuijl, Table of n, a(n) for n = 1..10000

FORMULA

Equals (3^(1/3)/2) * Gamma(1/3) * (AiryBi'(3^(1/3))/sqrt(3) - AiryAi'(3^(1/3))), where AiryAi' and AiryBi' are the derivatives of the Airy functions of the first and second kind, respectively.

EXAMPLE

2.131103503881489144...

MATHEMATICA

RealDigits[(3^(1/3)/2) Gamma[1/3] (AiryBiPrime[3^(1/3)]/Sqrt[3] - AiryAiPrime[3^(1/3)]), 10, 120][[1]]

CROSSREFS

Cf. A001113 (of factorials), A070910 (of factorials squared).

Cf. A395536-A395537, A395755-A395759 (pentagonal to 12-gonal).

Cf. A084941.

Sequence in context: A350004 A144966 A320000 * A119805 A111957 A125168

Adjacent sequences: A395752 A395753 A395754 * A395756 A395757 A395758

KEYWORD

nonn,cons,new

AUTHOR

Kelvin Voskuijl, May 05 2026

STATUS

approved