The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A180490 Numbers n such that (A000120(n))^2 divides n. 2
 1, 2, 4, 8, 12, 16, 20, 24, 32, 36, 40, 48, 64, 68, 72, 80, 81, 96, 128, 132, 136, 144, 160, 162, 192, 240, 252, 256, 260, 261, 264, 272, 288, 320, 324, 368, 384, 425, 432, 464, 480, 504, 512, 516, 520, 522, 528, 544, 576, 624, 625, 637, 640, 648, 675, 688, 720 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS This is a subsequence of A049445. LINKS Alois P. Heinz, Table of n, a(n) for n = 1..10000 FORMULA {n: (A000120(n))^2 | n}. MATHEMATICA fQ[n_] := Divisible[ n, DigitCount[n, 2, 1]^2]; Select[ Range@ 735, fQ] (* Robert G. Wilson v, Sep 10 2010 *) CROSSREFS Cf. A049445. Sequence in context: A048166 A335738 A010066 * A160408 A221707 A186146 Adjacent sequences:  A180487 A180488 A180489 * A180491 A180492 A180493 KEYWORD easy,nonn AUTHOR Ctibor O. Zizka, Sep 08 2010 EXTENSIONS a(43) onwards from Robert G. Wilson v, Sep 10 2010 STATUS approved

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

Last modified August 6 08:39 EDT 2020. Contains 336228 sequences. (Running on oeis4.)