This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A014537 #40 Feb 16 2025 08:32:33 %S A014537 4,31,227,1674,12367,91380,675214,4989191,36865412,272400600, %T A014537 2012783315,14872568831,109894245429,812014744422,6000022499693, %U A014537 44334502845080,327590128640500,2420581837980561,17885814992891026 %N A014537 Number of books required for n book-lengths of overhang in the harmonic book stacking problem. Sum_{i=1..a(n)} 1/i >= 2n and Sum_{i=1..a(n)-1} 1/i < 2n. %C A014537 Bisection of A002387. - _Robert G. Wilson v_, Jan 24 2017 %D A014537 R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Reading, MA, 1990, p. 259. %H A014537 Robert G. Wilson v, <a href="/A014537/b014537.txt">Table of n, a(n) for n = 1..1000</a> (terms 1..350 from Alois P. Heinz). %H A014537 Mike Paterson and Uri Zwick, <a href="http://arXiv.org/abs/0710.2357">Overhang</a>, arXiv:0710.2357 [math.HO], 2007. %H A014537 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BookStackingProblem.html">Book Stacking Problem</a> %F A014537 a(n) = A002387(2n), n>=1. Least a(n) with H(a(n)) > 2n with the harmonic numbers H(k):= A001008(k)/A002805(k). %t A014537 f[n_] := (k = Floor[ N [ E^(n - EulerGamma) + 1/(2n), 24]] - 2; While[ Floor[ N[ Log[k] + EulerGamma + 1/(2k) - 1/(12k^2) + 1/(120k^4), 24]] < n, k++ ]; k); Table[ f[n], {n, 2, 32, 2} ] %t A014537 a[n_] := k /. FindRoot[ HarmonicNumber[k] == 2*n, {k, Exp[2*n]}, WorkingPrecision -> 100] // Ceiling; Table[a[n], {n, 1, 100}] (* _Jean-François Alcover_, Jun 25 2013 *) %Y A014537 Cf. A002387. %K A014537 nonn,nice %O A014537 1,1 %A A014537 _Eric W. Weisstein_ %E A014537 More terms from _Robert G. Wilson v_, Dec 06 2001 %E A014537 Title corrected by _Jeremy Tan_, Sep 12 2020