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 A051862 #25 Aug 31 2024 10:25:42 %S A051862 0,1,11,376,20241,1427156,121639250,12007003824,1337583507153, %T A051862 165328009728652,22404009743110566,3299256277254713760, %U A051862 524366465815117346250,89448728780073829991976,16301356287284530869810308,3161258841758986060906197536,650090787950164885954804021185 %N A051862 Perturbation expansion in quantum field theory: scalar case in 6 spacetime dimensions. %H A051862 Michael Borinsky, Gerald V. Dunne, and Max Meynig, <a href="https://arxiv.org/abs/2104.00593">Semiclassical Trans-Series from the Perturbative Hopf-Algebraic Dyson-Schwinger Equations: phi^3 QFT in 6 Dimensions</a>, arXiv:2104.00593 [hep-th], 2021. %H A051862 Michael Borinsky, Gerald V. Dunne, and Karen Yeats, <a href="https://www.arxiv.org/abs/2408.15883">Tree-tubings and the combinatorics of resurgent Dyson-Schwinger equations</a>, arXiv:2408.15883 [math-ph], 2024. See pp. 10, 21. %H A051862 D. J. Broadhurst and D. Kreimer, <a href="http://arXiv.org/abs/hep-th/9912093">Combinatoric explosion of renormalization tamed by Hopf algebra: 30-loop Padé-Borel resummation</a>, arXiv:hep-th/9912093, 1999-2000. See also <a href="https://www.infona.pl/resource/bwmeta1.element.elsevier-ff9aba33-6f7c-3ed7-be8d-c0263813d125/tab/summary">Phys. Lett. B</a> (2000) Vol. 475, 63-70. %F A051862 The generating procedure is described by Broadhurst and Kreimer. %e A051862 a(31) = 7632236320181399967333968684399053053157812979126909028545984868160 was computed using Kreimer's Hopf algebra of rooted trees. It subsumes 2.6*10^21 terms in quantum field theory. %o A051862 (Sage) %o A051862 t = PowerSeriesRing(QQ, 't').gen() %o A051862 def shadok(c): %o A051862 """ %o A051862 fixed point procedure after G. Dunne talk at Kreimer's fest 2020 %o A051862 """ %o A051862 aa_sur_c = 2 * t * c.derivative() - c - 3 %o A051862 aa = c * aa_sur_c %o A051862 bb_sur_c = 2 * t * aa.derivative() - aa - 2 * aa_sur_c %o A051862 bb = c * bb_sur_c %o A051862 cc_sur_c = 2 * t * bb.derivative() - bb - bb_sur_c %o A051862 return 3 * t / cc_sur_c %o A051862 C = (-t / 2).O(2) %o A051862 for k in range(10): %o A051862 C = shadok(C) %o A051862 list(1 / 6 * C(-12 * t)) %o A051862 # _F. Chapoton_, Nov 19 2020 %Y A051862 Cf. A000699. %K A051862 nonn %O A051862 0,3 %A A051862 _David Broadhurst_, Dec 14 1999 %E A051862 a(0)=0 and more terms from _F. Chapoton_, Nov 19 2020