The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A054619 Triangle T(n,k) = Sum_{d|k} phi(d)*n^(k/d). 6
 1, 2, 6, 3, 12, 33, 4, 20, 72, 280, 5, 30, 135, 660, 3145, 6, 42, 228, 1344, 7800, 46956, 7, 56, 357, 2464, 16835, 118104, 823585, 8, 72, 528, 4176, 32800, 262800, 2097200, 16781472, 9, 90, 747, 6660, 59085, 532350, 4783023, 43053480, 387422001 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Alois P. Heinz, Rows n = 1..141, flattened EXAMPLE 1; 2, 6; 3, 12, 33; 4, 20, 72,  280; 5, 30, 135, 660,  3145; 6, 42, 228, 1344, 7800, 46956; ... MAPLE with(numtheory): T:= (n, k)-> add(phi(d)*n^(k/d), d=divisors(k)): seq(seq(T(n, k), k=1..n), n=1..10);  # Alois P. Heinz, Aug 28 2013 MATHEMATICA T[n_, k_] := Sum[EulerPhi[d]*n^(k/d), {d, Divisors[k]}]; Table[T[n, k], {n, 1, 10}, {k, 1, n}] // Flatten (* Jean-François Alcover, Feb 25 2015 *) PROG (PARI) T(n, k) = sumdiv(k, d, eulerphi(d)*n^(k/d)); \\ Michel Marcus, Feb 25 2015 CROSSREFS Cf. A054618, A054630, A054631, A185651 (transpose). Main diagonal gives: A228640. Sequence in context: A276158 A092393 A207901 * A054618 A120859 A253258 Adjacent sequences:  A054616 A054617 A054618 * A054620 A054621 A054622 KEYWORD nonn,tabl AUTHOR N. J. A. Sloane, Apr 16 2000 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 December 1 16:17 EST 2020. Contains 338844 sequences. (Running on oeis4.)