cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A159924 Triangle read by rows: a(m,m) = 1, for all m. For n < m, a(m,n) = a(m-1,n) + (sum of all terms in rows 1 through m-1).

Original entry on oeis.org

1, 2, 1, 6, 5, 1, 22, 21, 17, 1, 99, 98, 94, 78, 1, 546, 545, 541, 525, 448, 1, 3599, 3598, 3594, 3578, 3501, 3054, 1, 27577, 27576, 27572, 27556, 27479, 27032, 23979, 1, 240327, 240326, 240322, 240306, 240229, 239782, 236729, 212751, 1, 2343850
Offset: 1

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Author

Leroy Quet, Apr 26 2009

Keywords

Comments

Row sums are A159925. Sum of all terms in rows 1 through m is A159926(m). A159926(m) - A159926(m-1) = A159925(m), for m >= 2.

Examples

			The triangle starts like this:
1,
2,1,
6,5,1,
22,21,17,1
The sum of all these terms is 77. So adding 77 to each of the terms of the 4th row gets the fifth row: 22+77=99, 21+77=98, 17+77=94, 1+77=78, and the final terms is set at 1. So row 5 is: 99,98,94,78,1.
		

Crossrefs

Programs

  • Maple
    A159924 := proc(n,m) option remember ; local s; if n = m then 1; else s := add(add(procname(r,c),c=1..r),r=1..n-1) ; procname(n-1,m)+s ; fi; end: for n from 1 to 13 do for m from 1 to n do printf("%d,",A159924(n,m)) ; od: od: # R. J. Mathar, Apr 29 2009
  • Mathematica
    Block[{m = 0}, NestList[Block[{w = #}, AddTo[m, Total@ w]; Append[m + w, 1]] &, {1}, 9]] // Flatten (* Michael De Vlieger, Sep 23 2017 *)

Extensions

More terms from R. J. Mathar, Apr 29 2009