A130818 - OEIS

A130818

Decimal expansion of number whose Engel expansion is the sequence of squares, that is, 1, 4, 9, 16,...

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

(list; constant; graph; refs; listen; history; text; internal format)

OFFSET

1,2

REFERENCES

F. Engel "Entwicklung der Zahlen nach Stammbruechen" Verhandlungen der 52. Versammlung deutscher Philologen und Schulmaenner in Marburg. pp. 190-191, 1913.

LINKS

Table of n, a(n) for n=1..105.

Stephen Crowley, Two New Zeta Constants, page 17.

F. Engel, Entwicklung der Zahlen nach Stammbruechen, Verhandlungen der 52. Versammlung deutscher Philologen und Schulmaenner in Marburg, 1913, pp. 190-191. English translation by Georg Fischer, included with his permission.

Eric Weisstein's World of Mathematics, Engel Expansion

Eric Weisstein's World of Mathematics, Modified Bessel Function of the First Kind

FORMULA

Equal to Sum_{n>=1} 1/n!^2 or BesselI(0,2) - 1. - Gerald McGarvey, Nov 12 2007

Equals A070910 - 1. - R. J. Mathar, Jun 13 2008

MATHEMATICA

RealDigits[BesselI[0, 2] - 1, 10, 105] // First (* Jean-François Alcover, Oct 01 2013 *)

PROG

(PARI) besseli(0, 2)-1 \\ Charles R Greathouse IV, Oct 01 2013

CROSSREFS

Cf. A006784, A064648, A101689.

Sequence in context: A246672 A011054 A276140 * A339237 A363078 A377479