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A241016 Triangle read by rows: T(n, k) = sum of k-th row of n X n square filled with the numbers 1 through n^2 reading across rows left-to-right. 8

%I #28 Aug 23 2017 16:06:21

%S 1,3,7,6,15,24,10,26,42,58,15,40,65,90,115,21,57,93,129,165,201,28,77,

%T 126,175,224,273,322,36,100,164,228,292,356,420,484,45,126,207,288,

%U 369,450,531,612,693,55,155,255,355,455,555,655,755,855,955,66,187,308,429,550

%N Triangle read by rows: T(n, k) = sum of k-th row of n X n square filled with the numbers 1 through n^2 reading across rows left-to-right.

%C See illustration in links.

%C The corresponding triangle with column sums is found in A251630. - _Wolfdieter Lang_, Dec 09 2014

%H G. C. Greubel, <a href="/A241016/b241016.txt">Table of n, a(n) for the first 50 rows, flattened</a>

%H Kival Ngaokrajang, <a href="/A241016/a241016.pdf">Illustration of initial terms</a>

%F T(n, k) = Sum_{j=1..n} (n*(k-1)+ j), for n >= k >= 1. See the _Michel Marcus_ program. - _Wolfdieter Lang_, Dec 08 2014

%F T(n, k) = binomial(n+1, 2) + n^2*(k-1). - _Wolfdieter Lang_, Dec 09 2014

%e The triangle T(n, k) begins:

%e n\k 1 2 3 4 5 6 7 8 9 10 ...

%e 1: 1

%e 2: 3 7

%e 3: 6 15 24

%e 4: 10 26 42 58

%e 5: 15 40 65 90 115

%e 6: 21 57 93 129 165 201

%e 7: 28 77 126 175 224 273 322

%e 8: 36 100 164 228 292 356 420 484

%e 9: 45 126 207 288 369 450 531 612 693

%e 10: 55 155 255 355 455 555 655 755 855 955

%e ... reformatted - _Wolfdieter Lang_, Dec 08 2014

%t Table[Sum[n*(k - 1) + j, {j,1,n}], {n,1,10}, {k,1,n}] // Flatten (* _G. C. Greubel_, Aug 23 2017 *)

%o (Small Basic)

%o For n=1 To 20

%o For k=1 To n*n-(n-1) Step n

%o c=0

%o For i=1 To n

%o If i=1 Then

%o a=k

%o Else

%o a=a+1

%o EndIf

%o c=c+a

%o EndFor

%o TextWindow.Write(c+", ")

%o EndFor

%o EndFor

%o (PARI) trg(nn) = {for (n=1, nn, mm = matrix(n, n, i, j, j + n*(i-1)); for (i=1, n, print1(sum(j=1, n, mm[i, j]), ", ");); print(););} \\ _Michel Marcus_, Sep 15 2014

%Y Columns k=1..6: A000217, A005449, A005475, A022265, A022267, A022269.

%Y Diagonals: A081436, A059270, ...

%Y Row sums: A037270.

%K nonn,easy,tabl

%O 1,2

%A _Kival Ngaokrajang_, Aug 08 2014

%E Edited. - _Wolfdieter Lang_, Dec 08 2014

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Last modified April 25 04:42 EDT 2024. Contains 371964 sequences. (Running on oeis4.)