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 A258925 #12 Jun 18 2015 16:35:42 %S A258925 1,120,3024000,858574080000,1226178516326400000, %T A258925 5912338932461445120000000,75732595735526211882516480000000, %U A258925 2195068320271703663798288449536000000000,128322069958974226301129597680106864640000000000 %N A258925 E.g.f. satisfies: A(x) = Integral 1 + A(x)^5 dx. %H A258925 Vaclav Kotesovec, <a href="/A258925/b258925.txt">Table of n, a(n) for n = 0..90</a> %F A258925 E.g.f. A(x) satisfies: %F A258925 (1) A(x) = Series_Reversion( Integral 1/(1+x^5) dx ). %F A258925 Let C(x) = S'(x) such that S(x) = Series_Reversion( Integral 1/(1-x^5)^(1/5) dx ) is the e.g.f. of A258924, then e.g.f. A(x) of this sequence satisfies: %F A258925 (2) A(x) = S(x)/C(x), %F A258925 (3) A(x) = Integral 1/C(x)^5 dx. %F A258925 From _Vaclav Kotesovec_, Jun 18 2015: (Start) %F A258925 a(n) ~ 5^(5*n+5/2) * ((5-sqrt(5))/8)^(5*n/2+5/8) * (5*n)! * n^(1/4) / (sqrt(2) * Gamma(1/4) * Pi^(5*n+5/4)). %F A258925 a(n) ~ 5^(5*n+5/2) * sin(Pi/5)^(5*n+5/4) * (5*n)! * n^(1/4) / (sqrt(2) * Gamma(1/4) * Pi^(5*n+5/4)). %F A258925 (End) %e A258925 E.g.f.: A(x) = x + 120*x^6/6! + 3024000*x^11/11! + 858574080000*x^16/16! +... %e A258925 where Series_Reversion(A(x)) = x - x^6/6 + x^11/11 - x^16/16 + x^21/21 +... %e A258925 Also, A(x) = S(x)/C(x) where %e A258925 S(x) = x - 24*x^6/6! - 169344*x^11/11! - 25255286784*x^16/16! - 23089632627769344*x^21/21! +...+ A258924(n)*x^(5*n+1)/(5*n+1)! +... %e A258925 C(x) = 1 - 24*x^5/5! - 169344*x^10/10! - 25255286784*x^15/15! - 23089632627769344*x^20/20! +...+ A258924(n)*x^(5*n)/(5*n)! +... %e A258925 such that C(x)^5 + S(x)^5 = 1. %o A258925 (PARI) /* E.g.f. Series_Reversion( Integral 1/(1+x^5) dx ): */ %o A258925 {a(n) = local(A=x); A = serreverse( intformal( 1/(1 + x^5 + O(x^(5*n+2))) ) ); (5*n+1)!*polcoeff(A, 5*n+1)} %o A258925 for(n=0, 20, print1(a(n), ", ")) %o A258925 (PARI) /* E.g.f. A(x) = Integral 1 + A(x)^5 dx.: */ %o A258925 {a(n) = local(A=x); for(i=1, n+1, A = intformal( 1 + A^5 + O(x^(5*n+2)) )); (5*n+1)!*polcoeff(A, 5*n+1)} %o A258925 for(n=0, 20, print1(a(n), ", ")) %Y A258925 Cf. A258924, A258880, A258901, A258927, A259112, A259113, A258971. %K A258925 nonn %O A258925 0,2 %A A258925 _Paul D. Hanna_, Jun 15 2015