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A105364 Rearrangement of positive integers according to parity of (prime(n)-1)/2 (see comments). 1
2, 1, 4, 6, 3, 5, 8, 10, 7, 12, 9, 11, 14, 16, 13, 18, 15, 20, 22, 17, 24, 26, 19, 21, 23, 28, 30, 25, 27, 32, 34, 29, 36, 31, 38, 33, 40, 42, 35, 44, 37, 46, 39, 41, 48, 50, 52, 54, 43, 45, 56, 47, 58, 49, 60, 51, 62, 53, 55, 64, 57, 66, 68, 59, 61, 70, 63, 72, 65, 67, 74, 76 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If (prime(n+1)-1)/2 is even/odd then a(n) is the next odd/even number.

LINKS

Table of n, a(n) for n=1..72.

MATHEMATICA

bb={}; od=-1; ev=0; Do[If[OddQ[(Prime[i]-1)/2], ev=ev+2; bb=Append[bb, ev], od=od+2; bb=Append[bb, od]], {i, 2, 200}]; bb

CROSSREFS

Cf. A105363.

Sequence in context: A293387 A306015 A171087 * A180405 A171007 A209168

Adjacent sequences:  A105361 A105362 A105363 * A105365 A105366 A105367

KEYWORD

nonn

AUTHOR

Zak Seidov, Apr 01 2005

STATUS

approved

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Last modified February 27 19:10 EST 2020. Contains 332308 sequences. (Running on oeis4.)