A349815 Triangle read by rows: row 1 is [1]; for n >= 1, row n gives coefficients of expansion of (-1 - x + x^2 + x^3)*(1 + x + x^2 + x^3)^(n-1) in order of increasing powers of x.
1, -1, -1, 1, 1, -1, -2, -1, 0, 1, 2, 1, -1, -3, -4, -4, -2, 2, 4, 4, 3, 1, -1, -4, -8, -12, -13, -8, 0, 8, 13, 12, 8, 4, 1, -1, -5, -13, -25, -37, -41, -33, -13, 13, 33, 41, 37, 25, 13, 5, 1, -1, -6, -19, -44, -80, -116, -136, -124, -74, 0, 74, 124, 136, 116, 80, 44, 19, 6, 1, -1, -7, -26, -70, -149, -259, -376, -456, -450, -334, -124, 124, 334, 450, 456, 376, 259, 149, 70, 26, 7, 1
Offset: 0
Examples
Triangle begins: 1; -1, -1, 1, 1; -1, -2, -1, 0, 1, 2, 1; -1, -3, -4, -4, -2, 2, 4, 4, 3, 1; -1, -4, -8, -12, -13, -8, 0, 8, 13, 12, 8, 4, 1; -1, -5, -13, -25, -37, -41, -33, -13, 13, 33, 41, 37, 25, 13, 5, 1; ...
Links
- Jack Ramsay, On Arithmetical Triangles, The Pulse of Long Island, June 1965 [Mentions application to design of antenna arrays. Annotated scan.]
Crossrefs
Programs
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Maple
t1:=-1-x+x^2+x^3; m:=1+x+x^2+x^3; lprint([3]); for n from 1 to 12 do w1:=expand(t1*m^(n-1)); w4:=series(w1,x,3*n+1); w5:=seriestolist(w4); lprint(w5); od:
Comments