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 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). 4
 1, 2, 5, 10, 28, 50, 116, 178, 528, 1282, 2794, 4778, 10594, 17166, 33426, 60242, 183072, 304202, 759716, 1288642, 2965286, 6352098, 11776586, 18326642, 48714362, 95769336, 172377654, 417138342, 1004225842, 1633822142, 3266821106, 4706920002, 16520601024 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Robert G. Wilson v, Table of n, a(n) for n = 0..3000 FORMULA a(n) >= 2^n with equality for n <= 2. - Michel Marcus, Mar 19 2017 EXAMPLE 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. MATHEMATICA a[n_] := Sum[DivisorSigma[1, Binomial[n, i]], {i, 0, n}]; Table[a[i], {i, 1, 21}] PROG (PARI) a(n) = sum(k=0, n, sigma(binomial(n, k))); \\ Michel Marcus, Mar 17 2017 CROSSREFS Cf. A000079, A000203, A007318. Sequence in context: A032099 A243797 A120896 * A324838 A257889 A363388 Adjacent sequences: A074798 A074799 A074800 * A074802 A074803 A074804 KEYWORD easy,nonn AUTHOR Joseph L. Pe, Sep 30 2002 EXTENSIONS More terms from Carl Najafi, Oct 10 2011 Offset changed to 0 by Editors, Mar 19 2017 STATUS approved

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Last modified June 3 02:49 EDT 2023. Contains 363102 sequences. (Running on oeis4.)