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A128166 Numbers k such that k divides 1 + Sum_{j=1..k} prime(j)^2 = 1 + A024450(k). 91

%I #29 May 05 2021 18:15:13

%S 1,2,3,4,6,9,12,13,26,28,45,66,174,308,350,366,417,783,804,3774,5714,

%T 7998,17628,17940,63447,67620,83028,137868,216717,297486,425708,

%U 659316,674166,883500,1203786,3605052,6778607,9516098,19964862,25338586,27771732,70980884,91871891,208234138,231967260,238066596,289829748,784027092,1078515812,33256634230

%N Numbers k such that k divides 1 + Sum_{j=1..k} prime(j)^2 = 1 + A024450(k).

%C a(51) > 5.3*10^10. - _Robert Price_, Dec 16 2013

%C a(67) > 7*10^13. - _Bruce Garner_, May 05 2021

%H Bruce Garner, <a href="/A128166/b128166.txt">Table of n, a(n) for n = 1..66</a>

%H OEIS Wiki, <a href="https://oeis.org/wiki/Sums_of_primes_divisibility_sequences">Sums of powers of primes divisibility sequences</a>

%t s = 1; Do[s = s + Prime[n]^2; If[ Mod[s, n] == 0, Print[n]], {n, 700000}]

%t (* or *)

%t Select[Range[10^4], IntegerQ[(1 + Plus@@(Prime[Range[#]]^2))/#] &] (* _Alonso del Arte_, Jan 20 2011 *)

%Y Cf. A085450 (smallest m > 1 such that m divides Sum_{k=1..m} prime(k)^n).

%Y Cf. A007504, A045345, A171399, A128165, A233523, A050247, A050248.

%Y Cf. A024450, A111441, A217599, A128166, A233862, A217600, A217601.

%K hard,nonn

%O 1,2

%A _Alexander Adamchuk_, Feb 22 2007, Feb 23 2007

%E More terms from _Sean A. Irvine_, Jan 20 2011

%E a(45)-a(50) from _Robert Price_, Dec 16 2013

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Last modified April 25 05:18 EDT 2024. Contains 371964 sequences. (Running on oeis4.)