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%I #11 Aug 17 2021 02:17:49
%S 1,31,179,585,1463,3065,5729,9797,15737,24087,35315,50073,69025,92871,
%T 122475,158681,202529,254597,315957,387977,471589,568227,678971,
%U 805241,948515,1109675,1290839,1493127,1717571,1966997,2242925,2547277,2881033,3246087,3645459
%N a(n) = A115004(2n+1).
%H Chai Wah Wu, <a href="/A331759/b331759.txt">Table of n, a(n) for n = 0..10000</a>
%H N. J. A. Sloane, <a href="/A115004/a115004.txt">Families of Essentially Identical Sequences</a>, Mar 24 2021 (Includes this sequence)
%F a(n) = (2*n+1)^2 + Sum_{i=2..2n+1} (2*n+2-i)*(4*n+4-i)*phi(i). - _Chai Wah Wu_, Aug 17 2021
%o (Python)
%o from sympy import totient
%o def A331759(n): return (2*n+1)**2 + sum(totient(i)*(2*n+2-i)*(4*n+4-i) for i in range(2,2*n+2)) # _Chai Wah Wu_, Aug 17 2021
%Y Cf. A115004, A331760.
%K nonn
%O 0,2
%A _N. J. A. Sloane_, Feb 04 2020
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