cp's OEIS Frontend

A189562 Irregular triangle in which row n has even numbers k that have n solutions to the equation x' = k, where x' denotes the arithmetic derivative (A003415).

%I A189562 #6 Mar 30 2012 17:22:58
%S A189562 2,4,6,8,10,12,14,18,20,28,38,16,22,26,30,40,52,62,68,98,24,32,34,36,
%T A189562 42,44,46,50,56,58,88,122,128,54,64,70,74,76,82,86,94,104,136,148,152,
%U A189562 158,48,66,80,92,100,106,110,116,118,124,134,146,164,166,172,182
%N A189562 Irregular triangle in which row n has even numbers k that have n solutions to the equation x' = k, where x' denotes the arithmetic derivative (A003415).
%C A189562 The length of row n is A189561(n). The first term in row n is A189558(n).
%D A189562 See A003415.
%H A189562 T. D. Noe, <a href="/A189562/b189562.txt">Rows n = 0..250, flattened</a>
%F A189562 Row n has even numbers k such that A099302(k) = n.
%e A189562 The triangle begins:
%e A189562 2
%e A189562 4, 6, 8
%e A189562 10, 12, 14, 18, 20, 28, 38
%e A189562 16, 22, 26, 30, 40, 52, 62, 68, 98
%e A189562 24, 32, 34, 36, 42, 44, 46, 50, 56, 58, 88, 122, 128
%e A189562 54, 64, 70, 74, 76, 82, 86, 94, 104, 136, 148, 152, 158
%e A189562 48, 66, 80, 92, 100, 106, 110, 116, 118, 124, 134, 146, 164, 166, 172, 182
%Y A189562 Cf. A003415, A099302, A189561.
%K A189562 nonn,tabf
%O A189562 0,1
%A A189562 _T. D. Noe_, Apr 24 2011