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 A275755 #15 Aug 20 2016 22:57:13 %S A275755 1,1,2,6,19,65,234,873,3346,13099,52154,210541,859768,3545263, %T A275755 14741148,61736903,260192880,1102704585,4696416190,20090502706, %U A275755 86285786519,371917832707,1608317086940,6975728777332,30338392601498,132277349730004,578075052215714,2531710609461484,11109852467209553,48843541287179595,215108137824940916,948874606956945665,4191979050580762418,18545890698661636784,82159569800859439840,364432560308538162214,1618431087549954575022 %N A275755 G.f. satisfies: A(x) = x + A( A(x)^2 - A(x)^5 ). %C A275755 Compare to: C(x) = x + C( C(x)^2 - C(x)^4 ) holds when C(x) = x + C(x)^2 is a g.f. of the Catalan numbers (A000108). %H A275755 Paul D. Hanna, <a href="/A275755/b275755.txt">Table of n, a(n) for n = 1..300</a> %F A275755 G.f. satisfies: %F A275755 (1) A(x - A(x^2 - x^5)) = x. %F A275755 (2) A(x) = x + Sum_{n>=0} d^n/dx^n A(x^2-x^5)^(n+1) / (n+1)!. %F A275755 (3) A(x) = x * exp( Sum_{n>=0} d^n/dx^n A(x^2-x^5)^(n+1)/x / (n+1)! ). %e A275755 G.f.: A(x) = x + x^2 + 2*x^3 + 6*x^4 + 19*x^5 + 65*x^6 + 234*x^7 + 873*x^8 + 3346*x^9 + 13099*x^10 + 52154*x^11 + 210541*x^12 + 859768*x^13 + 3545263*x^14 +... %e A275755 such that A(x) = x + A( A(x)^2 - A(x)^5 ). %e A275755 RELATED SERIES. %e A275755 A(x)^2 = x^2 + 2*x^3 + 5*x^4 + 16*x^5 + 54*x^6 + 192*x^7 + 710*x^8 + 2702*x^9 + 10515*x^10 + 41660*x^11 + 167483*x^12 + 681532*x^13 + 2801816*x^14 +... %e A275755 A(x)^5 = x^5 + 5*x^6 + 20*x^7 + 80*x^8 + 320*x^9 + 1286*x^10 + 5210*x^11 + 21285*x^12 + 87655*x^13 + 363660*x^14 + 1518952*x^15 +... %e A275755 A(x^2 - x^5) = x^2 + x^4 - x^5 + 2*x^6 - 2*x^7 + 6*x^8 - 6*x^9 + 20*x^10 - 24*x^11 + 71*x^12 - 95*x^13 + 270*x^14 - 392*x^15 + 1063*x^16 - 1662*x^17 +... %e A275755 where Series_Reversion(A(x)) = x - A(x^2 - x^5). %o A275755 (PARI) {a(n) = my(A=x); for(i=1,n, A = x + subst(A,x, A^2 - A^5 +x*O(x^n))); polcoeff(A,n)} %o A275755 for(n=1,40,print1(a(n),", ")) %Y A275755 Cf. A275756, A275757, A275758, A141200. %K A275755 nonn %O A275755 1,3 %A A275755 _Paul D. Hanna_, Aug 20 2016