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 A002396 M2428 N0961 #27 Jul 22 2025 09:51:22 %S A002396 1,3,5,7,32,11,13,17,19,25,23,224,29,31,128,37,41,43,115,47,119,53,81, %T A002396 928,59,61,256,67,71,73,79,187,83,203,89,209,235,97,101,103,1696,107, %U A002396 109,121,113,295,287,127,512,131,299,137,139,319,323,149,151,157,1408 %N A002396 Inverse of reduced totient function. %C A002396 The position of the first i = 1, 2, 3, 4, 5, 6 .... in A002322 is 1, 3, 0, 5, 0, 7, 0, 32, 0, 11, 0, 13, 0, 0, 0, 17, 0, 19, 0, 25 with zeros if i is absent. Deleting the zeros (keeping A002202) defines this sequence. - _R. J. Mathar_, Jul 22 2025 %D A002396 D. H. Lehmer, Guide to Tables in the Theory of Numbers. Bulletin No. 105, National Research Council, Washington, DC, 1941, pp. 7-10. %D A002396 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A002396 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A002396 T. D. Noe, <a href="/A002396/b002396.txt">Table of n, a(n) for n = 1..1000</a> %H A002396 C. Moreau, <a href="http://www.numdam.org/item?id=NAM_1898_3_17__293_0">Sur quelques théorèmes d'arithmétique</a>, Nouvelles Annales de Mathématiques, 17 (1898), 293-307. %t A002396 max = 1000; Clear[a]; a[n_] := 100*n; a[2432] = 623104 (* given by _T. D. Noe_ *); For[m = 0; n = 1, m <= max, n = If[n == 1, 2, n + 2], For[k = n, k <= a[n], k++, If[CarmichaelLambda[k] == n, m++; Print[{n, m, k}]; a[m] = k; Break[]]]]; Table[a[n], {n, 1, max}] (* _Jean-François Alcover_, Jan 15 2015 *) %K A002396 nonn,nice,easy %O A002396 1,2 %A A002396 _N. J. A. Sloane_ %E A002396 More terms from Brent Lehman (mailbjl(AT)yahoo.com), Apr 26 2005