Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A125105
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A125105 Sub-array of triangular array A048004; also decomposition of sequence A008464. +0
2
1, 1, 4, 1, 12, 11, 1, 33, 47, 27, 1, 88, 185, 127, 63, 1, 232, 694, 563, 303, 143, 1, 609, 2526, 2400, 1394, 687, 319, 1, 1596, 9012, 9960, 6215, 3186, 1519, 703, 1, 4180, 31709, 40534, 27095, 14401, 7026, 3311, 1535, 1, 10945, 110469, 162538, 116143 (list; table; graph; listen)
OFFSET

1,3

COMMENT

A000079 counts compositions admitting a variety of triagular views; for example A048004 and A105147. The sub-table formed from the odd rows of A048004 have row sum 1,8,44,208,912,... and the remaining locations repeat sequence A045623.

FORMULA

T(n,k) = A048004(2*n-1,k), 0<=k<n. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 23 2007

EXAMPLE

The even rows of Table A048004 begin

1 1

1 4 2 1

1 12 11 5 2 1

etc.

so A125105 begins

1

1 4

1 12 11

etc.

MAPLE

A048004 := proc(n, k) option remember ; if k < 0 or k > n then 0; elif k = 0 or k = n then 1; else 2*A048004(n-1, k)+A048004(n-1, k-1)-2*A048004(n-2, k-1)+A048004(n-k-1, k-1)-A048004(n-k-2, k) ; fi ; end: A125105 := proc(n, k) A048004(2*n-1, k) ; end: for n from 1 to 13 do for k from 0 to n-1 do printf("%d ", A125105(n, k)) ; od: od: - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 23 2007

CROSSREFS

Cf. A000079 A008464 A045623 A048004 A105147 A125104.

Sequence in context: A130322 A106194 A051290 this_sequence A144878 A049424 A157394

Adjacent sequences: A125102 A125103 A125104 this_sequence A125106 A125107 A125108

KEYWORD

easy,nonn,tabl,uned

AUTHOR

Alford Arnold (Alford1940(AT)aol.com), Dec 07 2006

EXTENSIONS

More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 23 2007

page 1

Search completed in 0.002 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 November 30 13:13 EST 2009. Contains 167758 sequences.


AT&T Labs Research