This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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
 1, 2, 4, 6, 9, 12, 12, 16, 20, 24, 25, 30, 35, 40, 45, 48, 54, 60, 66, 72, 78, 84, 91, 98, 105, 112, 119, 126, 128, 136, 144, 152, 160, 168, 176, 184, 189, 198, 207, 216, 225, 234, 243, 252, 261, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 363, 374, 385, 396 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS 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. LINKS FORMULA T(n,k+1)=T(n,k)+n for 1<=k=2. - R. J. Mathar, Nov 01 2007 EXAMPLE Triangle starts 1; 2, 4; 6, 9, 12; 12, 16, 20, 24; 25, 30, 35, 40, 45; 48, 54, 60, 66, 72, 78; 84, 91, 98,105,112,119,126; 128,136,144,152,160,168,176,184; 189,198,207,216,225,234,243,252,261; MAPLE 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 CROSSREFS Cf. A033291. Sequence in context: A237685 A220768 A077220 * A258934 A225600 A183422 Adjacent sequences:  A128713 A128714 A128715 * A128717 A128718 A128719 KEYWORD easy,nonn,tabl AUTHOR Leroy Quet, Jun 12 2007 EXTENSIONS More terms from R. J. Mathar, Nov 01 2007 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 20 16:26 EDT 2019. Contains 324234 sequences. (Running on oeis4.)