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 A379195 #16 Jan 26 2025 02:43:50 %S A379195 1,1,1,2,5,10,21,56,148,359,906,2450,6571,17338,46777,128681,352859, %T A379195 967315,2679764,7474260,20860226,58375826,164197258,463322792, %U A379195 1309547562,3710517258,10543567357,30021808808,85628123727,244694423127,700553813377,2008780153580,5768264675938,16587793685429,47766704865133 %N A379195 G.f. A(x) satisfies x = Sum_{n=-oo..+oo} (A(x) - A(x)^n)^(n+1). %C A379195 Compare to the identity 0 = Sum_{n=-oo..+oo} (x - x^(n+1))^n. %H A379195 Paul D. Hanna, <a href="/A379195/b379195.txt">Table of n, a(n) for n = 1..1030</a> %F A379195 G.f. A(x) = Sum_{n>=1} a(n)*x^n satisfies the following formulas. %F A379195 (1) x = Sum_{n=-oo..+oo} (A(x) - A(x)^n)^(n+1). %F A379195 (2) x = Sum_{n=-oo..+oo} (-1)^n * A(x)^(n*(n-1)) / (1 - A(x)^(n+1))^(n-1). %F A379195 From _Paul D. Hanna_, Jan 25 2025: (Start) %F A379195 (3) x/A(x) = Sum_{n=-oo..+oo} (A(x) - A(x)^n)^n. %F A379195 (4) x/A(x) = Sum_{n=-oo..+oo, n<>-1} (-1)^n * A(x)^(n^2) / (1 - A(x)^(n+1))^n. %F A379195 (End) %F A379195 a(n) ~ c * d^n / n^(3/2), where d = 3.00914051453408723176675508018... and c = 0.174541635630216521276160108... - _Vaclav Kotesovec_, Jan 22 2025 %e A379195 G.f.: A(x) = x + x^2 + x^3 + 2*x^4 + 5*x^5 + 10*x^6 + 21*x^7 + 56*x^8 + 148*x^9 + 359*x^10 + 906*x^11 + 2450*x^12 + 6571*x^13 + 17338*x^14 + ... %e A379195 where x = Sum_{n=-oo..+oo} (A(x) - A(x)^n)^(n+1). %e A379195 RELATED SERIES. %e A379195 F(x) = Sum_{n=-oo..+oo} (x - x^n)^(n+1) = x - x^2 + x^3 - 2*x^4 + 3*x^5 - 3*x^6 + x^7 + x^8 + x^9 - 7*x^10 + 10*x^11 - 6*x^12 + x^13 + x^15 - 8*x^16 + 23*x^17 - 25*x^18 + x^19 + 17*x^20 + x^21 - 32*x^22 + 36*x^23 - 12*x^24 + x^25 + ... + A290003(n)*x^n + ... %e A379195 where F(A(x)) = x. %e A379195 SPECIFIC VALUES. %e A379195 A(t) = 1/2 at t = 0.30725396830704316799197832656390411971168116373389... %e A379195 where t = Sum_{n=-oo..+oo} (1/2 - 1/2^n)^(n+1), %e A379195 also, t = Sum_{n=-oo..+oo} (2^(n-1) - 1)^(n+1) / 2^(n*(n+1)). %e A379195 A(t) = 1/3 at t = 0.24338606674563424484910361835257533242309621632065... %e A379195 where t = Sum_{n=-oo..+oo} (1/3 - 1/3^n)^(n+1), %e A379195 also, t = Sum_{n=-oo..+oo} (3^(n-1) - 1)^(n+1) / 3^(n*(n+1)). %e A379195 A(t) = 1/4 at t = 0.19758524006807690544490179709803177425355852401229... %e A379195 where t = Sum_{n=-oo..+oo} (1/4 - 1/4^n)^(n+1). %e A379195 A(t) = 1/5 at t = 0.16558333624735433324843855679493132539350188690309... %e A379195 where t = Sum_{n=-oo..+oo} (1/5 - 1/5^n)^(n+1). %e A379195 A(1/4) = 0.34697020435026836163926019675791627488695303305268... %e A379195 where 1/4 = Sum_{n=-oo..+oo} (A(1/4) - A(1/4)^n)^(n+1). %e A379195 A(1/5) = 0.25400492231901630962271637839330240648984255624021... %e A379195 A(1/6) = 0.20160813481244983396982286666489080077373441727643... %e A379195 A(1/8) = 0.14327208862930858756346363646363969972815166338945... %o A379195 (PARI) N=40 \\ number of terms %o A379195 {a(n) = my(R = sum(m=-N-1, N+1, (x - x^m +x^2*O(x^N))^(m+1) ), A=x); %o A379195 A = serreverse(R); polcoef(A, n)} %o A379195 for(n=1, N, print1(a(n), ", ")) %Y A379195 Cf. A290003. %K A379195 nonn %O A379195 1,4 %A A379195 _Paul D. Hanna_, Jan 14 2025