Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A126441
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A126441 Tabular arrangement of the natural numbers: the row on which any non-zero term a(n) appears in is A053645(a(n))=A053645(n+1), and the column is A161511(a(n)). Table is presented by columns with 2^{k-1} items in column k, unused positions are filled with 0's. +0
10
1, 2, 3, 4, 5, 0, 7, 8, 9, 6, 11, 0, 0, 0, 15, 16, 17, 10, 19, 0, 13, 0, 23, 0, 0, 0, 0, 0, 0, 0, 31, 32, 33, 18, 35, 12, 21, 14, 39, 0, 0, 0, 27, 0, 0, 0, 47, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 63, 64, 65, 34, 67, 20, 37, 22, 71, 0, 25, 0, 43, 0, 29, 0, 79, 0, 0, 0, 0, 0, 0, 0, 55, 0, 0 (list; graph; listen)
OFFSET

0,2

COMMENT

Note: 1 might be a more natural starting offset for this sequence, although the identities concerning A053645 and A161511 would have to be changed. - Antti Karttunen, Oct 12 2009.

This can be regarded as an arrangement of the partitions, indexed by position in A125106. The partitions in a given row all have the same remaining partition when the largest part is removed; specifically, the partition indexed by the row number in A125106 (with row 0 having the empty partition remaining).

The first value on row n is A004760(n+1). The second value on each row is A004760(n+1) plus A062383(n); subsequent values increase by ever enlarging powers of two. Or equivalently, each subsequent value on the row after the first non-zero value is given by A004754(previous value on the same row).

A055941(r) tells how many terms the row r (>= 0) has been shifted rightward from its "natural position", i.e. with how many zeros that row has been prepended.

The number of (non-zero) entries in column k is A000041(k).

LINKS

A. Karttunen, Table of n, a(n) for n = 0..65534 (first 16 columns)

EXAMPLE

The largest power of 2 <= 6 is 4, 6 - 4 = 2, so 6 is in row 2. By A125106, 6 corresponds to the partition [2^2], total 4, so 6 goes in column 4. Thus T(2,4) = 6.

The table begins:

1.2.4..8.16.32.64.128.256.512.1024

..3.5..9.17.33.65.129.257.513.1025

.......6.10.18.34..66.130.258..514

....7.11.19.35.67.131.259.515.1027

............12.20..36..68.132..260

.........13.21.37..69.133.261..517

............14.22..38..70.134..262

......15.23.39.71.135.263.519.1031

...................24..40..72..136

...............25..41..73.137..265

...................26..42..74..138

............27.43..75.139.267..523

.......................28..44...76

...............29..45..77.141..269

...................30..46..78..142

.........31.47.79.143.271.527.1039

...........................48...80

.......................49..81..145

...........................50...82

...................51..83.147..275

PROGRAM

(GNU/MIT Scheme:)

(define (A126441 n) (A126441onebased (1+ n)))

(definec (A126441onebased n) (cond ((< n 2) n) (else (let ((prev (A126441onebased (- n (/ (A053644 n) 2))))) (if (or (= (A053644 n) (* 2 (A053644 (A053645 n)))) (zero? prev)) (let ((starter (A004760 (1+ (A053645 n))))) (if (> (A161511 starter) (1+ (A000523 n))) 0 starter)) (A004754 prev))))))

CROSSREFS

Cf. A125106, A053645, A000041, A004760, A062383, A000079 (column lengths).

A053645(a(A166274(n))) = A053645(1+A166274(n)) for all n>=1.

Positions of zeros: A166275, this sequence without zeros: A161924. A161920(n) gives the position of the first non-zero term on the row n-1.

Sequence in context: A095874 A063972 A063973 this_sequence A004181 A080744 A030548

Adjacent sequences: A126438 A126439 A126440 this_sequence A126442 A126443 A126444

KEYWORD

nonn,tabf

AUTHOR

Alford Arnold (Alford1940(AT)aol.com), Jan 19 2007

EXTENSIONS

Edited by Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Jan 23 2007. Further edited and Scheme-code added by Antti Karttunen (His-Firstname.His-Surname(AT)gmail.com), Oct 12 2009

page 1

Search completed in 0.003 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 15 00:47 EST 2009. Contains 170825 sequences.


AT&T Labs Research