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A172522 Partial sums of A049094. 0

%I #3 Mar 30 2012 18:40:50

%S 6,18,36,56,77,101,131,167,207,249,297,351,411,474,540,612,690,770,

%T 854,944,1040,1140,1242,1347,1455,1565,1679,1799,1925,2057,2193,2331,

%U 2471,2615,2762,2912,3067,3223,3383,3545,3713,3887,4067,4253,4442,4634,4832

%N Partial sums of A049094.

%C The subsequence of primes in this sequence begins: 101, 131, 167, 3067.

%F a(n) = SUM[i=1..n] {i such that 2^i - 1 is divisible by a square}.

%e a(20) = 6 + 12 + 18 + 20 + 21 + 24 + 30 + 36 + 40 + 42 + 48 + 54 + 60 + 63 + 66 + 72 + 78 + 80 + 84 + 90.

%Y Cf. A000040, A014491, A049093, A049096, A049095, A001220.

%K nonn

%O 1,1

%A _Jonathan Vos Post_, Feb 06 2010

%E More terms from _R. J. Mathar_, Feb 16 2010

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Last modified March 28 14:02 EDT 2024. Contains 371254 sequences. (Running on oeis4.)