The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A108319 Numbers of the form (2^i)*(3^j)*(7^k), with i, j, k >= 0. 6
 1, 2, 3, 4, 6, 7, 8, 9, 12, 14, 16, 18, 21, 24, 27, 28, 32, 36, 42, 48, 49, 54, 56, 63, 64, 72, 81, 84, 96, 98, 108, 112, 126, 128, 144, 147, 162, 168, 189, 192, 196, 216, 224, 243, 252, 256, 288, 294, 324, 336, 343, 378, 384, 392, 432, 441, 448, 486, 504, 512, 567 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Numbers m | 42^e with integer e >= 0. - Michael De Vlieger, Aug 22 2019 Sum_{n>=1} 1/a(n) = (2*3*7)/((2-1)*(3-1)*(7-1)) = 7/2. - Amiram Eldar, Sep 24 2020 LINKS Michael De Vlieger, Table of n, a(n) for n = 1..10000 FORMULA a(n) ~ exp((6*log(2)*log(3)*log(7)*n)^(1/3)) / sqrt(42). - Vaclav Kotesovec, Sep 23 2020 MATHEMATICA With[{n = 567}, Sort@ Flatten@ Table[2^i * 3^j * 7^k, {i, 0, Log2@ n}, {j, 0, Log[3, n/2^i]}, {k, 0, Log[7, n/(2^i*3^j)]}]] (* Michael De Vlieger, Aug 22 2019 *) CROSSREFS Cf. A051037, A003586, A003591, A003594. Sequence in context: A269804 A318400 A219174 * A177500 A018772 A134003 Adjacent sequences: A108316 A108317 A108318 * A108320 A108321 A108322 KEYWORD nonn,easy AUTHOR Douglas Winston (douglas.winston(AT)srupc.com), Jun 30 2005 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 6 18:28 EST 2022. Contains 358644 sequences. (Running on oeis4.)