# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a074801
Showing 1-1 of 1

%I A074801 #38 Jul 31 2021 23:01:54
%S A074801 1,2,5,10,28,50,116,178,528,1282,2794,4778,10594,17166,33426,60242,
%T A074801 183072,304202,759716,1288642,2965286,6352098,11776586,18326642,
%U A074801 48714362,95769336,172377654,417138342,1004225842,1633822142,3266821106,4706920002,16520601024
%N A074801 a(n) is the sum of the n-th row of the triangle formed by replacing each m in Pascal's triangle with sigma(m).
%H A074801 Robert G. Wilson v, <a href="/A074801/b074801.txt">Table of n, a(n) for n = 0..3000</a>
%F A074801 a(n) >= 2^n with equality for n <= 2. - _Michel Marcus_, Mar 19 2017
%e A074801 The third row of Pascal's triangle is 1 3 3 1. When each n here is replaced by sigma(n), the row becomes 1 4 4 1 with a sum of 10, so a(3) = 10.
%t A074801 a[n_] := Sum[DivisorSigma[1, Binomial[n, i]], {i, 0, n}]; Table[a[i], {i, 1, 21}]
%o A074801 (PARI) a(n) = sum(k=0, n, sigma(binomial(n, k))); \\ _Michel Marcus_, Mar 17 2017
%Y A074801 Cf. A000079, A000203, A007318.
%K A074801 easy,nonn
%O A074801 0,2
%A A074801 _Joseph L. Pe_, Sep 30 2002
%E A074801 More terms from _Carl Najafi_, Oct 10 2011
%E A074801 Offset changed to 0 by Editors, Mar 19 2017

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE