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A106555
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Concatenation of the two divisors of a semiprime, largest divisor first.
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0
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22, 32, 33, 52, 72, 53, 73, 112, 55, 132, 113, 172, 75, 192, 133, 232, 77, 173, 115, 193, 292, 312, 135, 233, 372, 117, 412, 175, 432, 293, 137, 313, 472, 195, 532, 373, 235, 592, 177, 1111, 612, 413, 433, 197, 672, 473, 712, 1311, 295, 732
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| First semiprime is 4; 4 is 2*2 -> 22.
Second semiprime is 6; 6 is 3*2 -> 32.
Third semiprime is 9; 9 is 3*3 -> 33.
Fourth semiprime is 10; 10 is 5*2 -> 52.
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PROG
| (PARI) glue(a, b)=10^#Str(b)*a+b;
for(n=4, 1e3, if(bigomega(n)==2, f=factor(n)[, 1]; print1(glue(f[#f], f[1])", "))) \\ Charles R Greathouse IV, Oct 04 2011
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CROSSREFS
| Sequence in context: A129073 A092215 A179282 * A106557 A142347 A121019
Adjacent sequences: A106552 A106553 A106554 * A106556 A106557 A106558
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KEYWORD
| base,easy,nonn
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AUTHOR
| Eric Angelini (eric.angelini(AT)kntv.be), May 09 2005
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