A098486 Odd numbers with replacement of all prime factors 3 by 2.

1, 2, 5, 7, 4, 11, 13, 10, 17, 19, 14, 23, 25, 8, 29, 31, 22, 35, 37, 26, 41, 43, 20, 47, 49, 34, 53, 55, 38, 59, 61, 28, 65, 67, 46, 71, 73, 50, 77, 79, 16, 83, 85, 58, 89, 91, 62, 95, 97, 44, 101, 103, 70, 107, 109, 74, 113, 115, 52, 119, 121, 82, 125, 127, 86, 131, 133

Offset

1,2

Comments

This sequence occurred in an analysis of A098003, see link.

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Keith Ramsay, Recursively Rotated Permutation. Posting in newsgroup sci.math, Sep 10 2004

Example

a(8): The 8th odd number is 15=3*5. Replace factor 3 by 2: a(8)=2*5=10.

Mathematica

Table[(2 n - 1)*(2/3)^IntegerExponent[2 n - 1, 3], {n, 67}] (* Ivan Neretin, Mar 05 2016 *)

Prog

(PARI) lista(nn) = {forstep(n=1, nn, 2, newn = if (np = valuation(n, 3), n*2^np/3^np, n); print1(newn, ", "); ); } \\ Michel Marcus, Mar 06 2016

Crossrefs

Cf. A098003, A005408.

Sequence in context: A296567 A205113 A349047 * A138320 A199275 A135007

Adjacent sequences: A098483 A098484 A098485 * A098487 A098488 A098489

Keyword

easy,nonn

Author

Hugo Pfoertner, Sep 10 2004

Status

approved