A074912 Triangle generated by Pascal's rule, except begin and end the n-th row with phi(n).

1, 1, 1, 2, 2, 2, 2, 4, 4, 2, 4, 6, 8, 6, 4, 2, 10, 14, 14, 10, 2, 6, 12, 24, 28, 24, 12, 6, 4, 18, 36, 52, 52, 36, 18, 4, 6, 22, 54, 88, 104, 88, 54, 22, 6, 4, 28, 76, 142, 192, 192, 142, 76, 28, 4, 10, 32, 104, 218, 334, 384, 334, 218, 104, 32, 10

Offset

1,4

Links

Table of n, a(n) for n=1..66.

Example

1;
1,1;
2,2,2;
2,4,4,2;
4,6,8,6,4;
2,10,14,14,10,2;
6,12,24,28,24,12,6;
4,18,36,52,52,36,18,4;
6,22,54,88,104,88,54,22,6;
4,28,76,142,192,192,142,76,28,4;

Maple

A074912 := proc(n, k) if k=1 or k=n then numtheory[phi](n); elif k > n or k < 1 then 0; else procname(n-1, k-1)+procname(n-1, k) ; end if; end proc: seq(seq(A074912(n, k), k=1..n), n=1..12); # R. J. Mathar, Aug 24 2011

Prog

(PARI) t(n, k) = {if ((k<1) || (k>n), return (0)); if ((k==1) || (k==n), return (eulerphi(n))); return (t(n-1, k-1)+t(n-1, k)); }
tabl(nn) = {for (n=1, nn, for (k=1, n, print1(t(n, k), ", "); ); /* print(); */); } \\ Michel Marcus, Nov 13 2014

Crossrefs

Sequence in context: A085311 A052273 A369291 * A274207 A158502 A331813

Adjacent sequences: A074909 A074910 A074911 * A074913 A074914 A074915

Keyword

easy,nonn,tabl

Author

Joseph L. Pe, Oct 01 2002

Extensions

More terms from Michel Marcus, Nov 13 2014

Status

approved