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!)
 A089999 Smallest triangular number with Hamming weight n (i.e., with exactly n 1's when written in binary). 5
 0, 1, 3, 21, 15, 55, 190, 253, 703, 3003, 5886, 13695, 4095, 49141, 106491, 192510, 784378, 1915903, 3407355, 5240703, 15986685, 30400503, 48201471, 124780503, 247431135, 602930175, 1608777726, 4290575295, 7482375615, 15938355070 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS A000120(a(n)) = n. a(n) = A000217(A211201(n)). - Reinhard Zumkeller, Mar 18 2013 LINKS Donovan Johnson, Table of n, a(n) for n = 0..60 MATHEMATICA a = Table[0, {30}]; Do[t = n(n + 1)/2; c = Count[ IntegerDigits[t, 2], 1]; If[ a[[c + 1]] == 0, a[[c + 1]] = t], {n, 1, 10^8}]; a (* Robert G. Wilson v, Dec 03 2003 *) PROG (Haskell) a089999 = a000217 . a211201  -- Reinhard Zumkeller, Mar 18 2013 CROSSREFS Cf. A211201, A000217, A089998, A061712, A090002. Sequence in context: A229197 A188721 A212996 * A124397 A216324 A226319 Adjacent sequences:  A089996 A089997 A089998 * A090000 A090001 A090002 KEYWORD nonn,base AUTHOR Reinhard Zumkeller, Nov 20 2003 EXTENSIONS More terms from Robert G. Wilson v, Dec 03 2003 Offset corrected by Donovan Johnson, May 01 2012 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 May 10 21:08 EDT 2021. Contains 343780 sequences. (Running on oeis4.)