A230123 Smallest number of the form 11*m+1 with exactly n prime factors, counted with multiplicity.

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

Links

Table of n, a(n) for n=0..31.

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

Adjacent sequences: A230120 A230121 A230122 * A230124 A230125 A230126

Keyword

nonn

Author

Elliott Line, Oct 10 2013

Status

approved