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A371321
Decimal expansion of Sum_{k>=0} 1/A007018(k).
1
1, 6, 9, 1, 0, 3, 0, 2, 0, 6, 7, 5, 7, 2, 5, 3, 9, 7, 4, 4, 3, 5, 6, 6, 2, 8, 4, 3, 1, 4, 5, 7, 4, 1, 7, 9, 3, 8, 0, 8, 5, 7, 7, 2, 4, 2, 5, 7, 9, 5, 2, 4, 9, 4, 4, 9, 6, 0, 4, 6, 6, 0, 5, 4, 0, 0, 0, 0, 5, 4, 3, 3, 8, 2, 4, 7, 3, 9, 6, 7, 9, 5, 6, 5, 8, 5, 4, 5, 6, 7, 8, 3, 1, 9, 0, 2, 1, 0, 3, 6, 5, 7, 0, 0, 3
OFFSET
1,2
COMMENTS
The corresponding alternating sum, Sum_{k>=0} (-1)^k/A007018(k), equals Cahen's constant (A118227).
Duverney et al. (2018) proved that this constant is transcendental.
Called the "Kellogg-Curtiss constant" by Sondow (2021), after the American mathematicians Oliver Dimon Kellogg (1878-1932) and David Raymond Curtiss (1878-1953).
The Engel expansion of this constant is 1 followed by the Sylvester sequence (A000058, see the Formula section).
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 6.7, p. 436.
LINKS
Brenda S. Baker and Edward G. Coffman, Jr., A tight asymptotic bound for next-fit-decreasing bin-packing, SIAM Journal on Algebraic Discrete Methods, Vol. 2, No. 2 (1981), pp. 147-152.
Daniel Duverney, Takeshi Kurosawa, and Iekata Shiokawa, Transcendence of numbers related with Cahen's constant, Moscow Journal of Combinatorics and Number Theory, Vol. 8, No. 1 (2018), pp. 57-69; alternative link.
Daniel Duverney, Takeshi Kurosawa, and Iekata Shiokawa. Irrationality exponents of certain fast converging series of rational numbers, Tsukuba Journal of Mathematics, Vol. 44, No. 2 (2020), pp. 235-250; alternative link.
Chan C. Lee and Der-Tsai Lee, A simple on-line bin-packing algorithm, Journal of the ACM (JACM), Vol. 32, No. 3 (1985), pp. 562-572. See p. 566.
Iekata Shiokawa, Irrationality exponents of certain alternating serries, Analytic Number Theory and Related Topics, Vol. 2162 (2020), pp. 210-215.
Jonathan Sondow, Irrationality and Transcendence of Alternating Series via Continued Fractions, in: A. Bostan and K. Raschel (eds.), Transcendence in Algebra, Combinatorics, Geometry and Number Theory, TRANS 2019. Springer Proceedings in Mathematics & Statistics, Vol. 373, Springer, Cham, 2021; arXiv preprint, arXiv:2009.14644 [math.NT], 2020.
Andrew Twigg and Eduardo C. Xavier, Locality-preserving allocations problems and coloured bin packing, Theoretical Computer Science, Vol. 596 (2015), pp. 12-22.
FORMULA
Equals 1 + Sum_{k>=1} 1/(Product_{i=0..k-1} A000058(i)).
EXAMPLE
1.69103020675725397443566284314574179380857724257952...
MATHEMATICA
s[0] = 2; s[n_] := s[n] = s[n - 1]^2 - s[n - 1] + 1; kmax = 1; FixedPoint[RealDigits[Sum[1/(s[k] - 1), {k, 0, kmax += 10}], 10, 120][[1]] &, kmax] (* after Jean-François Alcover at A118227 *)
PROG
(PARI) c = 1; 1 + suminf(k = 1, c += c^2; 1/c) \\ after Charles R Greathouse IV at A118227
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Amiram Eldar, Mar 19 2024
STATUS
approved