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A141674 Triangle T(n,m) read by rows: T(n,m) = sigma_0(n) * A126988(n,m). 1
1, 4, 2, 6, 0, 2, 12, 6, 0, 3, 10, 0, 0, 0, 2, 24, 12, 8, 0, 0, 4, 14, 0, 0, 0, 0, 0, 2, 32, 16, 0, 8, 0, 0, 0, 4, 27, 0, 9, 0, 0, 0, 0, 0, 3, 40, 20, 0, 0, 8, 0, 0, 0, 0, 4, 22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 72, 36, 24, 18, 0, 12, 0, 0, 0, 0, 0, 6, 26, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 56, 28, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums are {1, 6, 8, 21, 12, 48, 16, 60, 39, 72}.

LINKS

G. C. Greubel, Rows n = 1..100 of triangle, flattened

FORMULA

T(n,m) = sigma_0(n) * A126988(n,m).

T(n,m) = sigma_0(n) * if(m = 1, n, if(n mod m = 0, n/m, 0)).

EXAMPLE

Triangle begins

  { 1},

  { 4,  2},

  { 6,  0,  2},

  {12,  6,  0,  3},

  {10,  0,  0,  0,  2},

  {24, 12,  8,  0,  0,  4},

  {14,  0,  0,  0,  0,  0,  2},

  {32, 16,  0,  8,  0,  0,  0,  4},

  {27,  0,  9,  0,  0,  0,  0,  0,  3},

  {40, 20,  0,  0,  8,  0,  0,  0,  0,  4}

MATHEMATICA

t[n_, m_] = DivisorSigma[0, n]*If[m == 1, n, If[Mod[n, m] == 0, n/m, 0]]; Table[Table[t[n, m], {m, 1, n}], {n, 1, 10}]; Flatten[%]

CROSSREFS

Cf. A126988.

Sequence in context: A180109 A019170 A107504 * A329323 A178394 A266391

Adjacent sequences:  A141671 A141672 A141673 * A141675 A141676 A141677

KEYWORD

nonn,easy,less

AUTHOR

Roger L. Bagula and Gary W. Adamson, Sep 06 2008

EXTENSIONS

Edited by the Associate Editors of the OEIS, Jun 10 2018

STATUS

approved

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Last modified May 14 17:44 EDT 2021. Contains 343900 sequences. (Running on oeis4.)