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A228363 Sorted entries of the multiplication table a*b, with a>1, b>1. 1
4, 6, 6, 8, 8, 9, 10, 10, 12, 12, 12, 12, 14, 14, 15, 15, 16, 16, 16, 18, 18, 18, 18, 20, 20, 20, 20, 21, 21, 22, 22, 24, 24, 24, 24, 24, 24, 25, 26, 26, 27, 27, 28, 28, 28, 28, 30, 30, 30, 30, 30, 30, 32, 32, 32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 36, 36, 36, 36, 36, 38, 38, 39, 39, 40, 40, 40, 40 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Consists of the composite numbers (A002808), with the composite nonsquares (A089229) occurring more than once, i.e., the n-th composite appears A144925(n) times.
A complement of the primes (A000040).
LINKS
PROG
(PARI) L=listcreate(); for(k=2, 250, for(l=2, 250, listput(L, k*l))); v=vecsort(Vec(L)); for(n=1, 100, print1(v[n], ", "))
CROSSREFS
Cf. A061017 (sorted entries of standard multiplication table)
Sequence in context: A070259 A111653 A372786 * A334289 A173395 A305317
KEYWORD
nonn
AUTHOR
Ralf Stephan, Aug 21 2013
STATUS
approved

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Last modified May 30 02:46 EDT 2024. Contains 372957 sequences. (Running on oeis4.)