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A230123
Smallest number of the form 11*m+1 with exactly n prime factors, counted with multiplicity.
1
1, 23, 34, 12, 56, 243, 144, 320, 2432, 1728, 1024, 17920, 20736, 12288, 57344, 248832, 147456, 327680, 2490368, 1769472, 1048576, 18350080, 21233664, 12582912, 58720256, 254803968, 150994944, 335544320, 2550136832, 1811939328, 1073741824, 18790481920
OFFSET
0,2
FORMULA
a(n) = a(n-10)*2^10 for n >= 13.
EXAMPLE
The smallest number of the form 11*m+1 with exactly 8 prime factors is 2^7*19 = 11*221+1 = 2432.
MATHEMATICA
Join[{1}, Table[k = 1; While[Total[Transpose[FactorInteger[11*k + 1]][[2]]] != n, k++]; 11*k + 1, {n, 20}]] (* T. D. Noe, Oct 10 2013 *)
CROSSREFS
Sequence in context: A043909 A145566 A146595 * A049851 A353087 A223606
KEYWORD
nonn
AUTHOR
Elliott Line, Oct 10 2013
STATUS
approved