A140643 First differences of A140642.
1, 1, 1, 1, 1, 2, 2, 1, 1, 4, 4, 1, 1, 2, 8, 8, 2, 1, 1, 4, 16, 16, 4, 1, 1, 2, 8, 32, 32, 8, 2, 1, 1, 4, 16, 64, 64, 16, 4, 1
Offset: 0
Programs
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Mathematica
maxTerm = 384; FixedPoint[(nMax++; Print["nMax = ", nMax]; jj = Table[(2^n - (-1)^n)/3, {n, 0, nMax}]; Table[Differences[jj, n], {n, 0, nMax}] // Flatten // Abs // Union // Select[#, 0 < # <= maxTerm &] &) &, nMax = 5 ] // Differences (* Jean-François Alcover, Dec 16 2014 *)
Formula
Also a triangle on line (*): 1; 1, 1; 1, 1, 2; 2, 1, 1, 4; 4, 1, 1, 2, 8; 8, 2, 1, 1, 4, 16; 16, 4, 1, 1, 2, 8, 32; 32, 8, 2, 1, 1, 4, 16, 64; Row sums:1, 2, 4, 8, 16 =A000079(n). Note even palindromes finishing a row and beginning next one.
Comments