A386710 Decimal expansion of BesselI(2, 2 * sqrt(2)).

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

Offset: 1

Author

Kelvin Voskuijl, Jul 30 2025

Keywords

• nonn
• cons
• easy
• changed

Examples

			1.8575177802292191087705981876531371501390490911357...
		

Links

• Kelvin Voskuijl, Table of n, a(n) for n = 1..20000

Crossrefs

Cf. A386927 (continued fraction).

Cf. A096789 (for factorial squared).

Cf. A006472 (triangular polygorials).

Programs

Mathematica

RealDigits[BesselI[2, 2 * Sqrt[2]],10,100][[1]] (* Stefano Spezia, Aug 02 2025 *)

PARI

besseli(2, 2*sqrt(2)) \\ Amiram Eldar, Aug 02 2025

Formula

Equals Sum_{k >= 1} 2^k/((k-1)!*(k+1)!).