cp's OEIS Frontend

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.

A080056 Greedy powers of (2/Pi): Sum_{n=1..inf} (2/Pi)^a(n) = 1.

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%I A080056 #11 Sep 01 2025 22:12:26
%S A080056 1,3,5,16,22,24,28,34,37,43,45,49,51,54,57,59,65,68,70,74,80,88,94,97,
%T A080056 100,103,108,111,113,116,122,127,129,132,137,141,143,148,151,156,161,
%U A080056 164,166,172,174,177,184,189,202,204,208,213,216,219,225,227,238,247
%N A080056 Greedy powers of (2/Pi): Sum_{n=1..inf} (2/Pi)^a(n) = 1.
%C A080056 The n-th greedy power of x, when 0.5 < x < 1, is the smallest integer exponent a(n) that does not cause the power series Sum_{k=1..n} x^a(k) to exceed unity. A heuristic argument suggests that the limit of a(n)/n is m - Sum_{n=m..inf} log(1 + x^n)/log(x) = 4.2164448079..., where x=(2/Pi) and m=floor(log(1-x)/log(x))=2.
%C A080056 See A077468 for Mathematica program by _Robert G. Wilson v_.
%F A080056 a(n) = Sum_{k=1..n} floor(g_k) where g_1=1, g_{n+1}=log_x(x^frac(g_n) - x) (n>0) at x=(2/Pi) and frac(y) = y - floor(y).
%e A080056 a(3)=5 since (2/Pi) +(2/Pi)^3 +(2/Pi)^5 < 1 and (2/Pi) +(2/Pi)^3 +(2/Pi)^k > 1 for 3<k<5.
%Y A080056 Cf. A077468, A080055, A080057.
%K A080056 easy,nonn,changed
%O A080056 1,2
%A A080056 _Benoit Cloitre_ and _Paul D. Hanna_, Jan 23 2003