login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Triangle generated by Pascal's rule, except begin and end the n-th row with sigma(n).
0

%I #7 Feb 11 2014 19:05:30

%S 1,3,3,4,6,4,7,10,10,7,6,17,20,17,6,12,23,37,37,23,12,8,35,60,74,60,

%T 35,8,15,43,95,134,134,95,43,15,13,58,138,229,268,229,138,58,13,18,71,

%U 196,367,497,497,367,196,71,18

%N Triangle generated by Pascal's rule, except begin and end the n-th row with sigma(n).

%e Triangle begins:

%e 1;

%e 3, 3;

%e 4, 6, 4;

%e 7, 10, 10, 7;

%e 6, 17, 20, 17, 6;

%e 12, 23, 37, 37, 23, 12;

%e 8, 35, 60, 74, 60, 35, 8;

%o (PARI) t(n, k) = {if (k<1 || k>n, return (0)); if (k==1 || k==n, return (sigma(n))); return (t(n-1, k-1) + t(n-1, k));}

%o tabl(nn) = {for (n=1, nn, for (k=1, n, print1(t(n, k), ", ");); print(););} \\ _Michel Marcus_, May 19 2013

%K easy,nonn,tabl

%O 1,2

%A _Joseph L. Pe_, Sep 30 2002

%E More terms from _Michel Marcus_, May 19 2013