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 A366884 #21 Jan 03 2024 11:02:31 %S A366884 0,1,2,3,5,11,15,45,19,51,62,195,113,188,345,873,645,731,1890,911, %T A366884 3989,207,2405,3585,2950,10221,6525,18483,1709,15775,19569,12235, %U A366884 54718,43545,86515,12405,99215,9332,105447,51822,55885,290611,17753,120075,277203,408105,83505,605135,80565,562739,223191,432975,1533670 %N A366884 Number of branching factorizations of the least integer of each prime signature (A025487). %C A366884 Sequence appears to be injective, but can it be proved? This would prove also the conjectures given in A277120 and A366377. %C A366884 Of the first 21001 terms, there are 701 terms ending with digit "0", 614 with "1", 68 with "2", 570 with "3", 0 with "4", 17795 with "5", 0 with "6", 550 with "7", 67 with "8", and 636 with "9". Why such an overrepresentation (~ 85% of the total) of the terms of form 10k+5? Do any terms of the form 10k+4 or 10k+6 exist? See also the comments in A052886. %H A366884 Antti Karttunen, <a href="/A366884/b366884.txt">Table of n, a(n) for n = 1..21001</a> %H A366884 Michael De Vlieger, <a href="/A366884/a366884.png">Plot k = a(n) mod 10 at (x,y) = (n mod 144, 1 + floor(n/144))</a>, n = 1..20736, showing 0 in black, 1 in red, 2 in orange, 3 in yellow, 4 = dark green, 5 = bright green, 6 = cyan, 7 = light blue, 8 = dark blue, and 9 in purple. %F A366884 a(n) = A277120(A025487(n)). %F A366884 a(n) = A366377(A181815(n)). %F A366884 For all n >= 1, a(A025488(n)) = A007317(n), a(A098719(n)) = A052886(n). %Y A366884 Cf. A007317, A025487, A025488, A052886, A098719, A181815, A277120. %Y A366884 Permutation of A366377. %K A366884 nonn %O A366884 1,3 %A A366884 _Antti Karttunen_, Jan 02 2024