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A174895
a(n) = possible values of A007955(m) in increasing order, where A007955(m) = product of divisors of m.
5
1, 2, 3, 5, 7, 8, 11, 13, 17, 19, 23, 27, 29, 31, 36, 37, 41, 43, 47, 53, 59, 61, 64, 67, 71, 73, 79, 83, 89, 97, 100, 101, 103, 107, 109, 113, 125, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 196, 197, 199, 211, 223, 225, 227, 229, 233, 239
OFFSET
1,2
COMMENTS
a(n) = all values of A007955(m) in increasing order; all terms of sequence A007955 occur only once. Complement of A174896(n). A174897(a(n)) = 1, A174898(a(n)) = 0.
For every prime p, p and p^3 occur, as does the square of every semiprime pq with p and q distinct. - T. D. Noe, Oct 22 2010
For every prime p, every power p^t occurs, where t is a triangular number.
MATHEMATICA
nn=1000; Reap[Do[prod=Times@@Divisors[n]; If[prod<=nn, Sow[prod]], {n, nn}]][[2, 1]] (* T. D. Noe, Oct 22 2010 *)
PROG
(PARI) list(lim)=my(v=List(primes([2, lim]))); for(k=1, sqrtint(lim\=1), listput(v, factorback(divisors(k)))); forprime(p=2, sqrtnint(lim, 3), listput(v, p^3)); select(k->k<=lim, Set(v)) \\ Charles R Greathouse IV, Sep 22 2015
CROSSREFS
Sequence in context: A171561 A246551 A268391 * A375270 A186285 A375886
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 01 2010
EXTENSIONS
Corrected by Jaroslav Krizek, Apr 02 2010
Corrected and extended by T. D. Noe, Oct 22 2010
STATUS
approved