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

 

Logo

"Email this user" was broken Aug 14 to 9am Aug 16. If you sent someone a message in this period, please send it again.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A180050 Triangle T(n,k) read by rows. n>3,k=1 T(n,k)=A002321(n-1). The rest of the table is described by the recurrence in the Excel formula. 1
1, 1, 1, 1, 1, 1, -1, -2, -3, 1, -1, 1, 3, -3, 1, -2, -3, -3, 2, -3, 1, -1, 2, 2, 0, 2, -3, 1, -2, -4, -3, 0, -1, 2, -3, 1, -2, 2, 3, -3, 3, -1, 2, -3, 1, -2, -4, -4, 3, -4, 2, -1, 2, -3, 1, -1, 3, 4, -1, 0, -1, 2, -1, 2, -3, 1, -2, -5, -5, 1, 1, -1, -2, 2, -1, 2, -3, 1, -2, 3, 4, -4, 3, -1, 2 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,8

COMMENTS

Matrix inverse of A180051. Where the Excel formula says "randbetween(-9;9)" this table has the values of the Mertens function in the first column. Help with translating the spreadsheet formula would be appreciated.

LINKS

Table of n, a(n) for n=1..85.

FORMULA

Contribution from Mats Granvik, Aug 11 2010: (Start)

[from Wouter Meeussen, seqfan]

a(r,c)=0 /; c>r

a(r,c)=1 /; r<=3

a(r,1)=sum(Amu(k),k=1..r)

a(r,c)=a(r,c-1)-sum(a(r-j,c), j=1..c-1)/; c<=3

a(r,c)=sum(a(r-j,c-1), j=1..c-2)-sum(a(r-j,c), j=1..c-1)

(End)

EXAMPLE

Table begins:

1,

1,1,

1,1,1,

-1,-2,-3,1,

-1,1,3,-3,1,

-2,-3,-3,2,-3,1,

-1,2,2,0,2,-3,1,

-2,-4,-3,0,-1,2,-3,1,

-2,2,3,-3,3,-1,2,-3,1,

-2,-4,-4,3,-4,2,-1,2,-3,1,

-1,3,4,-1,0,-1,2,-1,2,-3,1,

-2,-5,-5,1,1,-1,-2,2,-1,2,-3,1,

-2,3,4,-4,3,-1,2,-2,2,-1,2,-3,1,

-3,-6,-5,3,-4,2,-2,1,-2,2,-1,2,-3,1,

MATHEMATICA

Contribution from Mats Granvik, Aug 11 2010: (Start)

[from Wouter Meeussen, seqfan]

Clear[a];

a[r_, c_]:=0 /; c>r;

a[r_, c_]:=1 /; r<=3;

a[r_, 1]:=Sum[MoebiusMu[k], {k, 0, r-1}];

a[r_, c_]:=a[r, c-1]-Sum[a[r-j, c], {j, 1, c-1}]/; c<=3;

a[r_, c_]:=a[r, c]=Sum[a[r-j, c-1], {j, 1, c-2}]-Sum[a[r-j, c], {j, 1, c-1}];

(m=Table[a[i, j], {i, 14}, {j, 14}])//ColumnForm

(End)

PROG

(Excel) Using European dot comma style:

=if(row()>=column(); if(row()<=3; 1; if(column()=1; randbetween(-9; 9); if(or(column()=2; column()=3); sum(indirect(address(row(); column()-1; 4)))-sum(indirect(address(row()-column()+1; column(); 4)&":"&address(row()-1; column(); 4); 4)); sum(indirect(address(row()-column()+2; column()-1; 4)&":"&address(row()-1; column()-1; 4); 4))-sum(indirect(address(row()-column()+1; column(); 4)&":"&address(row()-1; column(); 4); 4))))); 0)

CROSSREFS

Cf. A002321, A180051.

Sequence in context: A208879 A179617 A140188 * A275738 A202603 A279612

Adjacent sequences:  A180047 A180048 A180049 * A180051 A180052 A180053

KEYWORD

sign,tabl

AUTHOR

Mats Granvik, Aug 08 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified August 20 13:04 EDT 2017. Contains 290835 sequences.