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

0,1

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