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A097636
Odd composites of the form A024675(k) or 1+A024675(k), any k.
0
9, 15, 21, 27, 35, 39, 45, 51, 57, 65, 69, 77, 81, 87, 93, 99, 105, 111, 121, 129, 135, 145, 155, 161, 165, 171, 177, 187, 195, 205, 217, 225, 231, 237, 247, 255, 261, 267, 275, 279, 289, 301, 309, 315, 325, 335, 343, 351, 357, 363, 371, 377, 381, 387, 393, 399
OFFSET
1,1
COMMENTS
Start from an auxiliary sequence of interprimes, incremented by 1 if even: 5, 7, 9, 13, 15, 19, 21, 27, 31,... Removing the primes from this auxiliary sequence of odd numbers yields the current sequence.
MATHEMATICA
digits=200 (* find odd numbers between the primes nearest the average*) a=Table[If[(Mod[(Prime[n+1]+Prime[n])/2, 2]==1)&&( PrimeQ[(Prime[n+1]+Prime[n])/2]==False)&&( PrimeQ[(Prime[n+1]+Prime[n])/2+1]==False), (Prime[n+1]+Prime[n])/2, (Prime[n+1]+Prime[n])/2+1], {n, 2, digits}] b=Table[Prime[n], {n, 1, digits}] (* eliminate the primes from the sequence *) aa=Complement[a, b]
CROSSREFS
Sequence in context: A172181 A063139 A163170 * A179384 A225513 A331662
KEYWORD
nonn,easy,less
AUTHOR
Roger L. Bagula, Sep 20 2004
EXTENSIONS
Definition clarified by the Assoc. Eds. of the OEIS, Jul 13 2010
STATUS
approved