A098352 - OEIS

%I #13 Sep 08 2022 08:45:15

%S 4,8,8,12,16,12,16,24,24,16,20,32,36,32,20,24,40,48,48,40,24,28,48,60,

%T 64,60,48,28,32,56,72,80,80,72,56,32,36,64,84,96,100,96,84,64,36,40,

%U 72,96,112,120,120,112,96,72,40,44,80,108,128,140,144,140,128,108,80,44

%N Multiplication table of the even numbers read by antidiagonals.

%H G. C. Greubel, <a href="/A098352/b098352.txt">Antidiagonals n = 1..100, flattened</a>

%F T(n,k) = 4*A003991(n,k). - _R. J. Mathar_, Dec 08 2015

%e    4   8  12  16  20  24  28  32

%e    8  16  24  32  40  48  56  64

%e   12  24  36  48  60  72  84  96

%e   16  32  48  64  80  96 112 128

%e   20  40  60  80 100 120 140 160

%e   24  48  72  96 120 144 168 192

%e   28  56  84 112 140 168 196 224

%e   32  64  96 128 160 192 224 256

%p seq(seq(4*k*(n-k+1), k = 1..n), n = 1..12); # _G. C. Greubel_, Aug 16 2019

%t Table[4*k*(n-k+1), {n,12}, {k,n}]//Flatten (* _G. C. Greubel_, Aug 16 2019 *)

%o (PARI) T(n,k) = 4*k*(n-k+1); \\ _G. C. Greubel_, Aug 16 2019

%o (Magma) [4*k*(n-k+1): k in [1..n], n in [1..12]]; // _G. C. Greubel_, Aug 16 2019

%o (Sage) [[4*k*(n-k+1) for k in (1..n)] for n in (1..12)] # _G. C. Greubel_, Aug 16 2019

%o (GAP) Flat(List([1..12], n-> List([1..n], k-> 4*k*(n-k+1) ))); # _G. C. Greubel_, Aug 16 2019

%Y Cf. A003991, A098353.

%K nonn,tabl,easy

%O 1,1

%A Douglas Stones (dssto1(AT)student.monash.edu.au), Sep 04 2004