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 A345190 #9 May 21 2022 08:29:25 %S A345190 1,5,30,229,1938,17530,165852,1621133,16242474,165923854,1721675460, %T A345190 18095802306,192256162740,2061367432212,22276538889912, %U A345190 242387718986301,2653259550491034,29198054511893638,322835545567447092,3584671507685675894,39955514234936341980,446897274497509974508 %N A345190 Number of rows with the value "true" in the Kleene truth tables of all bracketed formulae with n distinct propositions p1, ..., pn connected by the binary connective of implication. %H A345190 G. C. Greubel, <a href="/A345190/b345190.txt">Table of n, a(n) for n = 1..925</a> %H A345190 Volkan Yildiz, <a href="https://arxiv.org/abs/2106.04728">Notes on algebraic structure of truth tables of bracketed formulae connected by implications</a>, arXiv:2106.04728 [math.CO], 2021. %F A345190 G.f.: (4-sqrt(1-12*x)-sqrt(5+24*x+4*sqrt(1-12*x)))/6. %F A345190 a(n) = 2*A005159(n-1) - A345189(n). - _G. C. Greubel_, May 20 2022 %t A345190 CoefficientList[Series[(4 -Sqrt[1-12*x] -Sqrt[5 +24*x +4*Sqrt[1-12*x]])/6, {x, 0, 40}], x]//Rest (* _G. C. Greubel_, May 20 2022 *) %o A345190 (PARI) my(x='x+O('x^30)); Vec((4-sqrt(1-12*x)-sqrt(5+24*x+4*sqrt(1-12*x)))/6) %o A345190 (SageMath) %o A345190 def A345190_list(prec): %o A345190 P.<x> = PowerSeriesRing(ZZ, prec) %o A345190 return P( (4-sqrt(1-12*x)-sqrt(5+24*x+4*sqrt(1-12*x)))/6 ).list() %o A345190 a=A345190_list(40); a[1:] # _G. C. Greubel_, May 20 2022 %Y A345190 Cf. A005159 (unknown rows, shifted), A025226 (all rows), A345189 (false rows). %K A345190 nonn %O A345190 1,2 %A A345190 _Michel Marcus_, Jun 10 2021