The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A143238 a(n) = A000203(n) * A024916(n). 1
 1, 12, 32, 105, 126, 396, 328, 840, 897, 1566, 1188, 3556, 1974, 3960, 4536, 6820, 4284, 10803, 5940, 14238, 11872, 14652, 10344, 29460, 16182, 23688, 24160, 36960, 20700, 54864, 25408, 53991, 43440, 51786, 48336, 99918, 43168, 71760, 70112, 120780, 58128, 142080 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..42. FORMULA a(n) = A000203(n) * A024916(n) = row sums of triangle A143237. EXAMPLE a(4) = 105 = A000203(4) * A024916(4) = 7 * 15. a(4) = 105 = sum of row 4 terms of triangle A143237: (7, + 21, + 28 + 49). MATHEMATICA sigma = Table[DivisorSigma[1, n], {n, 1, 50}]; sigma * Accumulate[sigma] (* Amiram Eldar, Feb 26 2020 *) CROSSREFS Cf. A000203, A024916, A143237. Sequence in context: A242543 A194644 A068381 * A102091 A303079 A268769 Adjacent sequences: A143235 A143236 A143237 * A143239 A143240 A143241 KEYWORD nonn AUTHOR Gary W. Adamson, Aug 01 2008 EXTENSIONS More terms from Amiram Eldar, Feb 26 2020 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 28 06:10 EDT 2023. Contains 362992 sequences. (Running on oeis4.)