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A129081 Primes appearing in partial sums of A030433 (primes ending in 9). 3

%I #17 May 19 2018 02:31:32

%S 19,107,523,1279,1787,4091,16103,18041,46889,68437,104561,155443,

%T 161641,174367,187573,303473,330587,359231,419929,430517,634793,

%U 878939,974507,1469753,1510319,1700851,1902653,2836961,2982841,3476299,3807589

%N Primes appearing in partial sums of A030433 (primes ending in 9).

%H Muniru A Asiru, <a href="/A129081/b129081.txt">Table of n, a(n) for n = 1..3000</a>

%F a(n) = A030433(1)+A030433(2)+...+A030433(x); a is a prime number.

%e a(5) = 1787 because 1787 = A030433(1) + A030433(2) + A030433(3) + A030433(4) + A030433(5) + A030433(6) + A030433(7) + A030433(8) + A030433(9) + A030433(10) + A030433(11) + A030433(12) + A030433(13) = 19 + 29 + 59 + 79 + 89 + 109 + 139 + 149 + 179 + 199 + 229 + 239 + 269; and 1787 is a prime number.

%t With[{pr9s=Select[Prime[Range[3000]],Last[IntegerDigits[#]]==9&]}, Select[ Accumulate[ pr9s],PrimeQ]] (* _Harvey P. Dale_, Dec 31 2011 *)

%o (PARI) {s=0; forprime(p=2, 17300, if(p%10==9, s+=p; if(isprime(s), print1(s, ","))))} /* _Klaus Brockhaus_, May 13 2007 */

%o (GAP) P:=Filtered(List([1..5*10^5],n->10*n+9),IsPrime);;

%o a:=Filtered(List([1..Length(P)],i->Sum([1..i],k->P[k])),IsPrime); # _Muniru A Asiru_, Apr 28 2018

%Y Cf. A030433, A000040.

%K easy,base,nonn

%O 1,1

%A _Tomas Xordan_, May 11 2007

%E Entries checked by _Klaus Brockhaus_, May 13 2007

%E Better description from _Harvey P. Dale_, Dec 31 2011

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Last modified April 23 13:04 EDT 2024. Contains 371913 sequences. (Running on oeis4.)