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 A339215 #15 Aug 08 2025 03:24:27 %S A339215 1,4,11,18,25,32,35,42,49,56,63,66,73,80,87,94,97,104,111,118,125,128, %T A339215 135,142,149,156,159,166,173,180,187,190,197,204,229,236,243,246,253, %U A339215 260,267,274,277,284,291,298,305,308,315,322,329,336,339,346,353,360 %N A339215 Primorial-base self numbers: numbers not of the form k + A276150(k). %C A339215 Analogous to self numbers (A003052) using primorial base representation (A049345) instead of decimal expansion. %C A339215 The numbers of terms that do not exceed 10^k, for k = 0, 1, ..., are 1, 2, 17, 150, 1469, 14669, 146680, 1466723, 14667162, 146671527, 1466715137, ... . Apparently, the asymptotic density of this sequence exists and equals 0.1466715... . - _Amiram Eldar_, Aug 08 2025 %D A339215 József Sándor and Borislav Crstici, Handbook of Number theory II, Kluwer Academic Publishers, 2004, Chapter 4, pp. 384-386. %H A339215 Amiram Eldar, <a href="/A339215/b339215.txt">Table of n, a(n) for n = 1..10000</a> %H A339215 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SelfNumber.html">Self Number</a>. %H A339215 Wikipedia, <a href="https://en.wikipedia.org/wiki/Mixed_radix#Primorial_number_system">Primorial number system</a>. %H A339215 Wikipedia, <a href="http://en.wikipedia.org/wiki/Self_number">Self number</a>. %H A339215 <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a> %t A339215 max = 4; bases = Prime@Range[max, 1, -1]; m = Times @@ bases; s[n_] := n + Plus @@ IntegerDigits[n, MixedRadix[bases]]; Complement[Range[m], Array[s, m]] %Y A339215 Cf. A003052, A010061, A010064, A010067, A010070, A049345, A276150, A333426, A339211, A339212, A339213, A339214. %K A339215 nonn,base %O A339215 1,2 %A A339215 _Amiram Eldar_, Nov 27 2020