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A103935 Choose a(n) to be the smallest odd number not yet used such that: a(1) = 1, a(2n) = composite, a(2n+1) = prime and partial sums are alternately composite or prime. 1
1, 9, 3, 15, 13, 21, 5, 25, 11, 27, 7, 33, 23, 35, 29, 39, 17, 45, 31, 49, 19, 51, 61, 55, 37, 57, 43, 63, 53, 65, 41, 69, 71, 75, 79, 77, 73, 81, 59, 85, 47, 87, 103, 91, 83, 93, 113, 95, 109, 99, 127, 105, 149, 111, 139, 115, 89, 117, 107, 119, 97, 121, 131, 123, 67, 125 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..66.

CROSSREFS

Cf. A075593, A075594, A103824, A103825, A103934.

Sequence in context: A329653 A170874 A309791 * A040077 A195312 A248311

Adjacent sequences:  A103932 A103933 A103934 * A103936 A103937 A103938

KEYWORD

nonn

AUTHOR

Ray Chandler Feb 21 2005, based on a suggestion from Zak Seidov.

STATUS

approved

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Last modified April 20 03:02 EDT 2021. Contains 343121 sequences. (Running on oeis4.)