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 A122668 #19 May 03 2025 09:40:09 %S A122668 1,2,2,3,2,4,2,4,3,4,2,6,2,4,4,5,2,6,2,6,4,4,2,8,3,4,4,6,2,8,2,6,4,4, %T A122668 4,9,2,4,4,8,2,8,2,6,6,4,2,48,3,6,4,6,2,8,4,8,4,4,2,62,2,4,6,7,4,8,2, %U A122668 6,4,8,2,74,2,4,6,6,4,8,2,80,5,4,2,86,4,4,4,8,2,92,4,6,4,4,4,98,2,6,6,9 %N A122668 a(n) = d(n)_n where d() = A000005. %C A122668 See A122618 for notation. %H A122668 Antti Karttunen, <a href="/A122668/b122668.txt">Table of n, a(n) for n = 1..10000</a> %e A122668 From _Antti Karttunen_, Aug 24 2017: (Start) %e A122668 For n = 48, A000005(48) = 10, in decimal "10". This read in base-48 is 1*(48^1) + 0*(48^0) = 48, thus a(48) = 48, which is the first time this sequence differs from A000005. %e A122668 For n = 60, A000005(60) = 12, in decimal "12". This read in sexagesimal base is 1*(60^1) + 2*(60^0), thus a(60) = 62. (End) %t A122668 a[n_]:=FromDigits[IntegerDigits[DivisorSigma[0,n]], n]; Array[a, 100] (* _Stefano Spezia_, May 03 2025 *) %o A122668 (PARI) %o A122668 A122618(n, d=digits(n)) = d*vectorv(#d, i, n^(#d-i)); \\ _M. F. Hasler_, Apr 22 2015 %o A122668 A122668(n) = A122618(n,digits(numdiv(n))); \\ _Antti Karttunen_, Aug 24 2017 %Y A122668 Cf. A000005, A122618, A122667. %K A122668 nonn,base %O A122668 1,2 %A A122668 _N. J. A. Sloane_, Sep 22 2006