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%I #12 Mar 02 2015 16:08:46
%S 3,4,10,5,12,21,6,14,24,36,7,16,27,40,55,8,18,30,44,60,78,9,20,33,48,
%T 65,84,105,10,22,36,52,70,90,112,136,11,24,39,56,75,96,119,144,171,12,
%U 26,42,60,80,102,126,152,180,210,13,28,45,64,85,108,133,160,189,220
%N Radius of B-excircle of Pythagorean triangle with a=(n+1)^2-m^2, b=2*(n+1)*m and c=(n+1)^2+m^2.
%C See a comment for excircle and exradius on A063929, also for links.
%F T(n,m) = m(n+m+1), n >= m >= 1.
%F T(n,m) = sqrt(s*(s-a)*(s-c)/(s-b)) with the semiperimeter s = (a + b + c)/2, and the a, b and c values given in the name substituted. - _Wolfdieter Lang_, Dec 02 2014
%e The triangle T(n, m) begins:
%e n\m 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 ...
%e 1: 3
%e 2: 4 10
%e 3: 5 12 21
%e 4: 6 14 24 36
%e 5: 7 16 27 40 55
%e 6: 8 18 30 44 60 78
%e 7: 9 20 33 48 65 84 105
%e 8: 10 22 36 52 70 90 112 136
%e 9: 11 24 39 56 75 96 119 144 171
%e 10: 12 26 42 60 80 102 126 152 180 210
%e 11: 13 28 45 64 85 108 133 160 189 220 253
%e 12: 14 30 48 68 90 114 140 168 198 230 264 300
%e 13: 15 32 51 72 95 120 147 176 207 240 275 312 351
%e 14: 16 34 54 76 100 126 154 184 216 250 286 324 364 406
%e 15: 17 36 57 80 105 132 161 192 225 260 297 336 377 420 465
%e ...
%e [Formatted and extended by _Wolfdieter Lang_, Dec 02 2014]
%Y Cf. A003991 (inradius), A063929 (A-exradius), A001283 (C-exradius), A055096 (circumradius diameter).
%K easy,nonn,tabl
%O 1,1
%A _Floor van Lamoen_, Aug 21 2001
%E Crossreferences commented and A055096 added by _Wolfdieter Lang_, Dec 02 2014
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