[go: up one dir, main page]

login
A213948
Triangle, by rows, generated from the INVERT transforms of (1, 1, 2, 4, 8, 16, ...).
2
1, 1, 1, 1, 2, 2, 1, 4, 4, 4, 1, 7, 10, 8, 8, 1, 12, 24, 20, 16, 16, 1, 20, 52, 56, 40, 32, 32, 1, 33, 112, 144, 112, 80, 64, 64, 1, 54, 238, 344, 320, 224, 160, 128, 128, 1, 88, 496, 828, 848, 640, 448, 320, 256, 256
OFFSET
1,5
COMMENTS
Row sums = A001519, the odd-indexed Fibonacci terms. The triangle is a companion to A213947, having row sums of the even-indexed Fibonacci terms.
FORMULA
Create an array in which the n-th row is the INVERT transform of the first n terms in the sequence (1, 1, 2, 4, 8, 16, 32, ...):
1, 1, 1, 1, 1, 1,
1, 2, 3, 5, 8, 13, (essentially A000045)
1, 2, 5, 9, 18, 37, (essentially A077947)
1, 2, 5, 13, 26, 57,
Terms of the n-th row of the triangle are the finite differences downwards the n-th column of this array.
EXAMPLE
First few rows of the triangle are:
1;
1, 1;
1, 2, 2;
1, 4, 4, 4;
1, 7, 20, 8, 8;
1, 12, 24, 20, 16, 16;
1, 20, 52, 56, 40, 32, 32;
1, 33, 112, 144, 112, 80, 64, 64;
1, 54, 238, 344, 320, 224, 160, 128, 128;
1, 88, 496, 828, 848, 640, 448, 320, 256, 256;
...
MAPLE
read("transforms") ;
A213948i := proc(n, k)
if n = 1 then
L := [1, seq(0, i=0..k)] ;
else
L := [1, seq(2^i, i=0..n-2), seq(0, i=0..k)] ;
end if;
INVERT(L) ;
op(k, %) ;
end proc:
A213948 := proc(n, k)
if k = 1 then
1;
else
A213948i(k, n)-A213948i(k-1, n) ;
end if;
end proc: # R. J. Mathar, Jun 30 2012
CROSSREFS
Cf. A001519, A213947, A000071 (2nd column), A020714 (subdiagonal), A005009 (subdiagonal).
Sequence in context: A319534 A061436 A214095 * A136787 A165038 A305191
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Jun 25 2012
STATUS
approved