A169957 a(1) = 1, then a(n) is the smallest number such that a(a(n)) = 2n+1.

1, 3, 5, 6, 7, 9, 11, 10, 13, 17, 15, 14, 19, 25, 23, 18, 21, 33, 27, 22, 35, 41, 31, 26, 29, 49, 39, 30, 51, 57, 47, 34, 37, 65, 43, 38, 67, 73, 55, 42, 45, 81, 71, 46, 83, 89, 63, 50, 53, 97, 59, 54, 99, 105, 79, 58, 61, 113, 103, 62, 115

Offset: 1

Author

Eric Angelini, Aug 02 2010

Keywords

• nonn
• easy
• look

Comments

Original name was "Similar to A079905, but without the 'monotonically increasing sequence' condition."

Links

• Yifan Xie, Table of n, a(n) for n = 1..10000 (first 499 terms from Charlie Neder)

Crossrefs

Cf. A080653, A079905, A169956.

Formula

a(1) = 1, a(2) = 3, a(4k) = 4k + 2, all other terms follow from the criterion defining the sequence. - Charlie Neder, Dec 21 2018

Extensions

a(25)-a(61) from Charlie Neder, Dec 21 2018

Name changed by Charlie Neder, Dec 22 2018