This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A182534 #19 Jan 30 2013 03:32:49 %S A182534 1,1,2,2,2,3,5,4,2,6,14,10,3,4,10,42,28,6,6,5,20,132,84,14,12,6,10,35, %T A182534 429,264,36,28,10,12,14,70,1430,858,99,72,20,20,14,28,126,4862,2860, %U A182534 286,198,45,40,20,28,42,252 %N A182534 Array read by antidiagonals: coefficient of the Euler-Mascheroni constant in below expression. %C A182534 The (i,j)-entry of the array is the coefficient of the Euler-Mascheroni constant in: -2^(i+2j-1)/Pi*int(log(x)*cos(x)^i*sin(x)^(2j-1)/x, x=0..infinity); see Mathematica code below. %C A182534 First row: A000108. %C A182534 Second row: -A002420. %C A182534 Third row: A007054. %C A182534 Fourth row: A002421. %C A182534 Fifth row: A007272. %C A182534 Sixth row: -A002422. %C A182534 Eighth row: A002423. %C A182534 First column: A001405. %C A182534 Second column: A089408. %C A182534 Odd entries on main diagonal: A126596. %e A182534 Evaluate: -256/Pi*int(cos(x)^3*log(x)*sin(x)^5/x, x=0..infinity) = 3*eulergamma-log(9/8). Thus the (3,3) entry of the array is 3, the coefficient of the Euler-Mascheroni constant in this expression. %e A182534 The array begins as: %e A182534 | 1 1 2 5 14 42 132 429 ... | %e A182534 | 2 2 4 10 28 84 264 858 ... | %e A182534 | 3 2 3 6 14 36 99 286 ... | %e A182534 | 6 4 6 12 28 72 198 572 ... | %e A182534 | 10 5 6 10 20 45 110 286 ... | %e A182534 | 20 10 12 20 40 90 220 572 ... | %e A182534 | 35 14 14 20 35 70 154 364 ... | %e A182534 | 70 28 28 40 70 140 308 728 ... | %e A182534 | ... ... ... ... ... ... ... ... ... | %t A182534 A[a_, b_] := %t A182534 A[a, b] = %t A182534 Array[Coefficient[ %t A182534 Integrate[ %t A182534 Log[x]*Cos[x]^#1*Sin[x]^(2 #2 - 1)/x, {x, 0, %t A182534 Infinity}] (2^(#1 + 2 #2 - 1))/(-\[Pi]), EulerGamma] &, {a, b}]; %t A182534 A[11, 11]; %t A182534 Print[A[11, 11] // MatrixForm]; %t A182534 Table2 = {}; %t A182534 k = 1; %t A182534 While[k < 11, Table1 = {}; %t A182534 i = 1; %t A182534 j = k; %t A182534 While[0 < j, %t A182534 AppendTo[Table1, %t A182534 First[Take[First[Take[A[11, 11], {i, i}]], {j, j}]]]; %t A182534 j = j - 1; %t A182534 i = i + 1]; %t A182534 AppendTo[Table2, Table1]; %t A182534 k++]; %t A182534 Print[Flatten[Table2]] %Y A182534 Cf. A000108, A002420, A007054, A002421, A007272, A002422, A002423, A001405, A089408, A126596. %K A182534 nonn,tabl %O A182534 1,3 %A A182534 _John M. Campbell_, May 05 2012