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 A109673 Hexagonal pyramid related to Prouhet-Tarry problem. 6

%I

%S 1,1,1,1,3,1,1,1,1,2,1,2,8,8,2,1,8,15,8,1,2,8,8,2,1,2,1,1,3,3,1,3,15,

%T 24,15,3,3,24,60,60,24,3,1,15,60,93,60,15,1,3,24,60,60,24,3,3,15,24,

%U 15,3,1,3,3,1,1,4,6,4,1,4,24,52,52,24,4,6,52,160,228,160,52,6,4,52

%N Hexagonal pyramid related to Prouhet-Tarry problem.

%C Entries of slices [n,n] in A109672, read by rows.

%C Greatest numbers in each slice (central numbers) form A002893 : 1, 3, 15, 93, 639, ...

%F Sum of terms in slice [n, n] = 3^(2n); example : 1+2+1+2+8+15+8+1+2+8+8+2+1+2+1 = 3^4 = 81 for the slice [2, 2].

%e Slice [0, 0]:

%e ... 1 ...

%e Slice [1,1]:

%e ... 1 1 ...

%e .. 1 3 1 ...

%e ... 1 1 ...

%e Slice [2,2]:

%e .... 1 2 1 ...

%e ... 2 8 8 2 ...

%e .. 1 8 15 8 1 ...

%e ... 2 8 8 2 ...

%e .... 1 2 1 ....

%e Slice [3,3]:

%e ...... 1 3 3 1 .....

%e .... 3 15 24 15 3 ...

%e ... 3 24 60 60 24 3 ...

%e .. 1 15 60 93 60 15 1 ...

%e ... 3 24 60 60 24 3 ...

%e .... 3 15 24 15 3 ....

%e ...... 1 3 3 1 ....

%K nonn,tabf,easy

%O 0,5

%A _Philippe Deléham_, Aug 07 2005

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Last modified December 3 22:32 EST 2021. Contains 349468 sequences. (Running on oeis4.)