A135762 Start with sequence of positive integers, then swap a(i) and a(i-1) if a(i) is an odd prime.

1, 3, 2, 5, 4, 7, 6, 8, 9, 11, 10, 13, 12, 14, 15, 17, 16, 19, 18, 20, 21, 23, 22, 24, 25, 26, 27, 29, 28, 31, 30, 32, 33, 34, 35, 37, 36, 38, 39, 41, 40, 43, 42, 44, 45, 47, 46, 48, 49, 50, 51, 53, 52, 54, 55, 56, 57, 59, 58, 61, 60, 62, 63, 64, 65, 67, 66, 68, 69, 71, 70, 73

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Example

a(1)=1; then
a(2)=3 and a(3)=2 because p=3 is odd prime and p and p-1 are swapped.

Mathematica

r=Range[100]; Do[If[PrimeQ[r[[i]]], {r[[i]], r[[i-1]]}={r[[i-1]], r[[i]]}], {i, 3, 97, 2}]; r

Crossrefs

Cf. A135761.

Sequence in context: A297208 A301941 A344547 * A344548 A341903 A066250

Adjacent sequences: A135759 A135760 A135761 * A135763 A135764 A135765

Keyword

nonn

Author

Zak Seidov, Nov 27 2007

Status

approved