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).

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

Offset: 0

Author

T. D. Noe, Apr 24 2011

Keywords

• nonn
• tabf

Comments

The length of row n is A189561(n). The first term in row n is A189558(n).

Examples

			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
		

References

• See A003415.

Links

• T. D. Noe, Rows n = 0..250, flattened

Crossrefs

Cf. A003415, A099302, A189561.

Formula

Row n has even numbers k such that A099302(k) = n.