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 A128716 Triangle where the n-th row, of n terms in order, contains consecutive multiples of n. The smallest term of row n is the smallest integer >= the largest term of row (n-1), for n >= 2. 1

%I

%S 1,2,4,6,9,12,12,16,20,24,25,30,35,40,45,48,54,60,66,72,78,84,91,98,

%T 105,112,119,126,128,136,144,152,160,168,176,184,189,198,207,216,225,

%U 234,243,252,261,270,280,290,300,310,320,330,340,350,360,363,374,385,396

%N Triangle where the n-th row, of n terms in order, contains consecutive multiples of n. The smallest term of row n is the smallest integer >= the largest term of row (n-1), for n >= 2.

%C If we instead had the triangle where the smallest term of row n is the smallest integer strictly > the largest term of row (n-1), for n >= 2, then we would have sequence A033291.

%F T(n,k+1)=T(n,k)+n for 1<=k<n. T(n,1)=n*ceil[T(n-1,n-1)/n] for n>=2. - _R. J. Mathar_, Nov 01 2007

%e Triangle starts

%e 1;

%e 2, 4;

%e 6, 9, 12;

%e 12, 16, 20, 24;

%e 25, 30, 35, 40, 45;

%e 48, 54, 60, 66, 72, 78;

%e 84, 91, 98,105,112,119,126;

%e 128,136,144,152,160,168,176,184;

%e 189,198,207,216,225,234,243,252,261;

%p A128716 := proc(n,k) option remember ; if n = 1 then 1 ; elif k = 1 then n*ceil(A128716(n-1,n-1)/n) ; else A128716(n,k-1)+n ; fi ; end: for n from 1 to 11 do for k from 1 to n do printf("%d,",A128716(n,k)) ; od: od: # _R. J. Mathar_, Nov 01 2007

%Y Cf. A033291.

%K easy,nonn,tabl

%O 1,2

%A _Leroy Quet_, Jun 12 2007

%E More terms from _R. J. Mathar_, Nov 01 2007

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Last modified July 24 14:27 EDT 2017. Contains 289773 sequences.