A271641 Quantity of ancestors for n (in the sense explained below)

9, 17, 15, 13, 11, 9, 7, 5, 3, 1, 17, 32, 29, 25, 21, 17, 13, 9, 5, 2, 15, 28, 26, 23, 19, 15, 11, 7, 4, 2, 13, 24, 22, 20, 17, 13, 9, 6, 4, 2, 11, 20, 18, 16, 14, 11, 8, 6, 4, 2, 9, 16, 14, 12, 10, 9, 8, 6, 4, 2, 7, 12, 10, 8, 7, 7, 7, 6, 4, 2, 5, 8, 6, 5, 5, 5, 5, 5, 4, 2, 3, 4, 3, 3, 3, 3, 3, 3, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 17, 32

Offset

0,1

Comments

See A271639 for the definition of an ancestor.

Links

Table of n, a(n) for n=0..101.

Example

"0" has 9 ancestors, which are 11, 22, 33, 44, 55, 66, 77, 88 and 99; "1" has 17 ancestors, which are 10, 12, 21, 23, 32, 34, 43, 45, 54, 56, 65, 67, 76, 78, 87, 89, 98;  "2" has 15 ancestors, which are 13, 20, 24, 31, 35, 42, 46, 53, 57, 64, 68, 75, 79, 86, 97; "3" has 13 ancestors, etc. Thus the sequence starts with 9, 17, 15, 13, etc.

Crossrefs

Cf. A271639.

Sequence in context: A190322 A184938 A103707 * A292410 A004751 A134104

Adjacent sequences: A271638 A271639 A271640 * A271642 A271643 A271644

Keyword

nonn,base

Author

Eric Angelini and Jean-Marc Falcoz, Apr 11 2016

Status

approved