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 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). 3
 2, 4, 6, 8, 10, 12, 14, 18, 20, 28, 38, 16, 22, 26, 30, 40, 52, 62, 68, 98, 24, 32, 34, 36, 42, 44, 46, 50, 56, 58, 88, 122, 128, 54, 64, 70, 74, 76, 82, 86, 94, 104, 136, 148, 152, 158, 48, 66, 80, 92, 100, 106, 110, 116, 118, 124, 134, 146, 164, 166, 172, 182 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS The length of row n is A189561(n). The first term in row n is A189558(n). REFERENCES See A003415. LINKS T. D. Noe, Rows n = 0..250, flattened FORMULA Row n has even numbers k such that A099302(k) = n. EXAMPLE The triangle begins: 2 4, 6, 8 10, 12, 14, 18, 20, 28, 38 16, 22, 26, 30, 40, 52, 62, 68, 98 24, 32, 34, 36, 42, 44, 46, 50, 56, 58, 88, 122, 128 54, 64, 70, 74, 76, 82, 86, 94, 104, 136, 148, 152, 158 48, 66, 80, 92, 100, 106, 110, 116, 118, 124, 134, 146, 164, 166, 172, 182 CROSSREFS Cf. A003415, A099302, A189561. Sequence in context: A321501 A238264 A098807 * A194372 A058218 A264986 Adjacent sequences:  A189559 A189560 A189561 * A189563 A189564 A189565 KEYWORD nonn,tabf AUTHOR T. D. Noe, Apr 24 2011 STATUS approved

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Last modified June 17 19:09 EDT 2021. Contains 345085 sequences. (Running on oeis4.)