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%I #4 Nov 01 2014 14:42:54
%S 2,12,30,42,72,110,156,210,272,342,380,420,462,552,650,756,870,992,
%T 1122,1260,1406,1560,1722,1892,2070,2256,2450,2652,2862,3080,3192,
%U 3422,3660,3906,4160,4422,4692,4970,5256,5550,5852,6162,6480,6806,7140,7482,7832
%N Oblong numbers in A249407.
%C A005369(a(n)) = 1.
%H Reinhard Zumkeller, <a href="/A249411/b249411.txt">Table of n, a(n) for n = 1..301</a>
%e Distribution of oblong numbers on A249406 and its complement,
%e m*(m+1) factorizations are shown in respective columns:
%e . n | A002378 | A249406 | A249407 n | A002378 | A249406 | A249407
%e . ---+---------+---------+-------- ---+---------+---------+--------
%e . 1 | 2 | | 1*2 13 | 182 | 13*14 |
%e . 2 | 6 | 2*3 | 14 | 210 | | 14*15
%e . 3 | 12 | | 3*4 15 | 240 | 15*16 |
%e . 4 | 20 | 4*5 | 16 | 272 | | 16*17
%e . 5 | 30 | | 5*6 17 | 306 | 17*18 |
%e . 6 | 42 | | 6*7 18 | 342 | | 18*19
%e . 7 | 56 | 7*8 | 19 | 380 | | 19*20
%e . 8 | 72 | | 8*9 20 | 420 | | 20*21
%e . 9 | 90 | 9*10 | 21 | 462 | | 21*22
%e . 10 | 110 | | 10*11 22 | 506 | 22*23 |
%e . 11 | 132 | 11*12 | 23 | 552 | | 23*24
%e . 12 | 156 | | 12*13 24 | 600 | 24*25 | .
%o (Haskell)
%o a249411 n = a249411_list !! (n-1)
%o a249411_list = filter ((== 1) . a005369) a249407_list
%Y Cf. A249407, A005369, subsequence of A002378.
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Oct 31 2014
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