A125199 Triangle read by rows: T(n,k) = 4*n*k - n - k, 1<=k<=n.

2, 5, 12, 8, 19, 30, 11, 26, 41, 56, 14, 33, 52, 71, 90, 17, 40, 63, 86, 109, 132, 20, 47, 74, 101, 128, 155, 182, 23, 54, 85, 116, 147, 178, 209, 240, 26, 61, 96, 131, 166, 201, 236, 271, 306, 29, 68, 107, 146, 185, 224, 263, 302, 341, 380, 32, 75, 118, 161, 204, 247

Offset

1,1

Comments

A124934 gives the range: for n,k with 1<=k<=n exists at least one m such that A124934(m)=T(n,k);

row sums give A125200; central terms give A125201;

T(n,1) = A016789(n-1);

T(n,2) = A017041(n-1) for n>1;

T(n,3) = A017485(n-1) for n>2;

T(n,n-1) = A125202(n) for n>1;

T(n,n) = A002939(n).

Links

Table of n, a(n) for n=1..61.

Mathematica

Flatten[Table[4*n*k-n-k, {n, 15}, {k, n}]] (* Harvey P. Dale, Nov 15 2014 *)

Crossrefs

Sequence in context: A151574 A110020 A070266 * A103832 A348891 A191368

Adjacent sequences: A125196 A125197 A125198 * A125200 A125201 A125202

Keyword

nonn,tabl

Author

Reinhard Zumkeller, Nov 24 2006

Status

approved