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 A090140 #14 Aug 17 2025 17:41:04 %S A090140 1,1,2,5,15,83,860,113147 %N A090140 Number of groups of order 7^n. %D A090140 G. Bagnera, La composizione dei Gruppi finiti il cui grado e la quinta potenza di un numero primo, Ann. Mat. Pura Appl. (3), 1 (1898), 137-228. %D A090140 Hans Ulrich Besche, Bettina Eick and E. A. O'Brien, A Millennium Project: Constructing Small Groups, International Journal of Algebra and Computation, Vol. 12, No 5 (2002), 623-644. %D A090140 W. Burnside, Theory of Groups of Finite Order, Dover, NY, 1955. %D A090140 M. F. Newman, E. A. O'Brien and M. R. Vaughan-Lee, Groups and nilpotent Lie rings whose order is the sixth power of a prime, J. Algebra, 278 (2004), 383-401. %D A090140 E. A. O'Brien and M. R. Vaughan-Lee, The groups of order p^7 for odd prime p, J. Algebra 292, 243-258, 2005. %F A090140 For a prime p >= 5, the number of groups of order p^n begins 1, 1, 2, 5, 15, 61 + 2*p + 2*gcd (p - 1, 3) + gcd (p - 1, 4), 3*p^2 + 39*p + 344 + 24*gcd(p - 1, 3) + 11*gcd(p - 1, 4) + 2*gcd(p - 1, 5), ... %Y A090140 Cf. A000001, A000679, A090091, A090130. %K A090140 nonn,more,hard %O A090140 0,3 %A A090140 _Eamonn O'Brien_, Jan 22 2004 %E A090140 Corrected and extended by _David Radcliffe_, Feb 24 2010 %E A090140 Updated reference for p^7 _Eamonn O'Brien_, Mar 06 2010