A171762 a(n) = Sum_{k=n^2+1..(n+1)^2-1} tau(k).

4, 12, 22, 34, 44, 58, 72, 88, 100, 120, 126, 148, 164, 182, 196, 220, 228, 254, 264, 284, 304, 328, 338, 358, 382, 400, 420, 444, 442, 478, 494, 518, 544, 564, 562, 602, 622, 648, 652, 690, 684, 730, 740, 768, 790, 812, 828, 858, 870, 898, 920, 946, 958, 990

Offset

1,1

Links

Table of n, a(n) for n=1..54.

Formula

a(n) = A168011(n) - A168011(n-1) - A048691(n). - R. J. Mathar, Jan 25 2010

Maple

A168011 := proc(n) add( numtheory[tau](k), k=1..n^2+2*n) ; end proc: A048691 := proc(n) numtheory[tau](n^2) ; end proc: A171762 := proc(n) A168011(n)-A168011(n-1)-A048691(n) ; end proc: seq(A171762(n), n=1..80) ; # R. J. Mathar, Jan 25 2010

Mathematica

Array[n \[Function] Sum[DivisorSigma[0, k], {k, n^2 + 1, (n + 1)^2 - 1}], 200] (* J. Mulder (jasper.mulder(AT)planet.nl), Jan 28 2010 *)

Crossrefs

Cf. A000005, A048691, A168011.

Sequence in context: A301263 A047956 A301228 * A210639 A301260 A301185

Adjacent sequences: A171759 A171760 A171761 * A171763 A171764 A171765

Keyword

nonn,easy

Author

Giovanni Teofilatto, Dec 18 2009

Extensions

Definition corrected by Giovanni Teofilatto, Dec 19 2009

More terms from R. J. Mathar and J. Mulder (jasper.mulder(AT)planet.nl), Jan 25 2010

Status

approved