A140255 Inverse Mobius transform of A014963.
1, 3, 4, 5, 6, 7, 8, 7, 7, 9, 12, 10, 14, 11, 10, 9, 18, 11, 20, 12, 12, 15, 24, 13, 11, 17, 10, 14, 30, 15, 32, 11, 16, 21, 14, 15, 38, 23, 18, 15, 42, 17, 44, 18, 14, 27, 48, 16, 15, 15, 22, 20, 54, 15, 18, 17, 24, 33, 60, 20, 62, 35, 16, 13, 20, 21, 68, 24, 28, 19, 72, 19, 74
Offset: 1
Keywords
Examples
a(4) = 5 = (1, 1, 0, 1) dot (1, 2, 3, 2) = (1 + 2 + 0 + 2); where (1, 1, 0, 1) = row 4 of triangle A051731 and (1, 2, 3, 2) = the first 4 terms of A014963.
Links
- Jodi Spitz, Table of n, a(n) for n = 1..5000
Programs
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PARI
expmangoldt(n)=ispower(n, , &n); if(isprime(n), n, 1); a(n) = sumdiv(n, d, expmangoldt(d)) \\ Jodi Spitz, Apr 11 2023
Formula
Equals row sums of triangle A140256. - Gary W. Adamson, May 16 2008
G.f.: Sum_{k>=1} M(k)*x^k/(1 - x^k), where M(k) is the exponential of Mangoldt function (A014963). - Ilya Gutkovskiy, Jan 16 2017
Extensions
More terms from R. J. Mathar, Jan 19 2009