A268673 a(0) = 0; a(1) = 1; for n > 1, a(n) = 1 + 4*A092246(n-1).

0, 1, 5, 29, 45, 53, 77, 85, 101, 125, 141, 149, 165, 189, 197, 221, 237, 245, 269, 277, 293, 317, 325, 349, 365, 373, 389, 413, 429, 437, 461, 469, 485, 509, 525, 533, 549, 573, 581, 605, 621, 629, 645, 669, 685, 693, 717, 725, 741, 765, 773, 797, 813, 821, 845, 853, 869, 893, 909, 917, 933, 957, 965, 989, 1005

Offset

0,3

Comments

Seems to be also the fixed points of permutations A268823 and A268824.

Links

Antti Karttunen, Table of n, a(n) for n = 0..10000

Formula

a(0) = 0; a(1) = 1; for n > 1, a(n) = 1 + 4*A092246(n-1).

Mathematica

Join[{0, 1}, 1 + 4 Select[Range[1, 251, 2], OddQ[Total[IntegerDigits[#, 2]]]&]] (* Jean-François Alcover, Mar 15 2016 *)

Prog

(Scheme)
(define (A268673 n) (if (<= n 1) n (+ 1 (* 4 (A092246 (- n 1))))))
(Python)
def A268673(n): return (((m:=n-2)<<4)+(13 if m.bit_count()&1 else 5)) if n>1 else n # Chai Wah Wu, Mar 03 2023

Crossrefs

Cf. A268823, A268824.

Cf. also A092246, A268717.

Many (but not all) terms of A013710 seem to be included.

Sequence in context: A156053 A081116 A192090 * A146829 A329151 A201712

Adjacent sequences: A268670 A268671 A268672 * A268674 A268675 A268676

Keyword

nonn

Author

Antti Karttunen, Feb 19 2016

Status

approved