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