login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A049501 Major index of n, first definition. 10
0, 0, 1, 0, 1, 1, 2, 0, 1, 1, 4, 1, 2, 2, 3, 0, 1, 1, 5, 1, 4, 4, 5, 1, 2, 2, 6, 2, 3, 3, 4, 0, 1, 1, 6, 1, 5, 5, 6, 1, 4, 4, 9, 4, 5, 5, 6, 1, 2, 2, 7, 2, 6, 6, 7, 2, 3, 3, 8, 3, 4, 4, 5, 0, 1, 1, 7, 1, 6, 6, 7, 1, 5, 5, 11, 5, 6, 6, 7, 1, 4, 4, 10, 4, 9, 9, 10, 4, 5, 5, 11, 5, 6, 6, 7, 1, 2, 2, 8, 2, 7, 7, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,7

REFERENCES

D. M. Bressoud, Proofs and Confirmations, Camb. Univ. Press, 1999; cf. p. 89.

LINKS

J. Stauduhar, Table of n, a(n) for n = 0..10000

FORMULA

Write n in binary; sum the positions where there is a '1' followed immediately to the right by a '0', counting the leftmost digit as position '1'.

EXAMPLE

50 = 110010 has 1's followed by 0's in positions 2 and 5 (reading from the left), so a(50)=7. At the beginning of the sequence we have 0->0, 1->0, 10->1, 11->0, 100->1, 101->1, 110->2, 111->0, 1000->1, 1001->1, 1010->1+3=4, ...

MATHEMATICA

a[n_] := Total[ Flatten[ Position[ IntegerDigits[n, 2] //. {b___, 1, 0, c___} -> {b, 2, 3, c}, 2]]]; Table[a[n], {n, 0, 102}] (* Jean-Fran├žois Alcover, Dec 20 2011 *)

Table[Total[Flatten[Position[Partition[IntegerDigits[n, 2], 2, 1], {1, 0}]]], {n, 0, 110}] (* Harvey P. Dale, Nov 04 2012 *)

CROSSREFS

Cf. A049502.

Sequence in context: A283272 A292166 A282192 * A102564 A215703 A292712

Adjacent sequences:  A049498 A049499 A049500 * A049502 A049503 A049504

KEYWORD

nonn,base,nice,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Erich Friedman, Feb 19 2000

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 17 01:09 EDT 2018. Contains 316275 sequences. (Running on oeis4.)