A225210 Least number of the form 11*m-1 with exactly n prime factors, counted with multiplicity.

43, 10, 76, 54, 32, 560, 648, 384, 1792, 7776, 4608, 10240, 77824, 55296, 32768, 573440, 663552, 393216, 1835008, 7962624, 4718592, 10485760, 79691776, 56623104, 33554432, 587202560, 679477248, 402653184, 1879048192, 8153726976, 4831838208, 10737418240, 81604378624, 57982058496, 34359738368

Offset

1,1

Comments

Corresponding values of m: 4, 1, 7, 5, 3, 51, 59, 35, 163, 707, 419, 931, 7075, 5027, 2979, 52131, 60323, 35747, 166819, 723875, 428963.

Links

Table of n, a(n) for n=1..35.

Formula

a(n) = a(n-10)*2^10 for n > 11.

Mathematica

Module[{nn=725000, f11}, f11={#, PrimeOmega[#]}&/@(11 Range[nn]-1); Table[SelectFirst[f11, #[[2]]==n&], {n, 21}]][[All, 1]] (* The program generates the first 21 terms of the sequence. To generate more, increase the value of the nn constant, but to generate all 35 terms listed nn will have to be increased to nearly 7-1/2 billion and the program will take a very long time to run. *) (* Harvey P. Dale, Dec 04 2021 *)

Prog

(PARI) {for(n = 1, 30, forstep(m = 10, 3276800, 11, if(bigomega(m) == n, print1(m", "); break())))}

Crossrefs

Inspired by A230123.

Sequence in context: A354085 A156677 A097398 * A033363 A187088 A127147

Adjacent sequences: A225207 A225208 A225209 * A225211 A225212 A225213

Keyword

nonn

Author

Zak Seidov, Oct 25 2013

Status

approved