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 A102218 #15 Feb 16 2025 08:32:55 %S A102218 4,8,10,12,14,15,22,26,27,35,42,44,45,54,56,58,60,62,63,64,65,68,78, %T A102218 84,85,88,90,92,94,96,99,102,108,111,118,119,121,122,123,126,129,133, %U A102218 136,138,141,143,145,152,155,158,159,160,161,164,165,166,169,174,175 %N A102218 2-Monica numbers. %C A102218 Composite numbers k such that the difference between the sum of digits of k (A007953) and the sum of sums of digits of the prime factors of k (taken with multiplicity, A118503) is even. - _Amiram Eldar_, Apr 23 2021 %D A102218 József Sándor and Borislav Crstici, Handbook of Number theory II, Kluwer Academic Publishers, 2004, Chapter 4, p. 384. %D A102218 James J. Tattersall, Elementary Number Theory in Nine Chapters, 2nd ed., Cambridge University Press, 2005, p. 93. %H A102218 Amiram Eldar, <a href="/A102218/b102218.txt">Table of n, a(n) for n = 1..10000</a> %H A102218 Michael Smith, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/34-2/smith.pdf">Cousins of Smith Numbers: Monica and Suzanne Sets</a>, Fibonacci Quarterly, Vol. 34, No. 2 (1996), pp. 102-104. %H A102218 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MonicaSet.html">Monica Set</a>. %t A102218 s[n_] := Plus @@ IntegerDigits[n]; f[p_, e_] := e*s[p]; sp[n_] := Plus @@ f @@@ FactorInteger[n]; mon2Q[n_] := CompositeQ[n] && EvenQ[s[n] - sp[n]]; Select[Range[200], mon2Q] (* _Amiram Eldar_, Apr 23 2021 *) %Y A102218 Cf. A007953, A018252, A102216, A102219, A118503, A177927. %K A102218 nonn,base %O A102218 1,1 %A A102218 _Eric W. Weisstein_, Dec 30 2004