A117528 Prime at which the cumulative sum in A117527 is prime.

2, 3, 13, 41, 43, 109, 137, 167, 181, 199, 307, 373, 421, 491, 587, 661, 1009, 1097, 1117, 1373, 1471, 1483, 1601, 1607, 1787, 1913, 2053, 2089, 2203, 2267, 2591, 2819, 2953, 3191, 3361, 3623, 3691, 3779, 3877, 4051

Offset: 1

Author

Enoch Haga, Mar 25 2006

Keywords

• easy
• nonn

Comments

At the twin primes 41 and 43, we obtain consecutive prime integer sums of 641 and 757.

Examples

			In a(5)=4007, multiplication of the prime 109*e resulted in the int sum 296. When added to previous sums, the total came to 4007, a prime.
		

Crossrefs

Cf. A117527 A117504.

Programs

UBASIC

10 Ct=1
20 B=nxtprm(B)
22 E=#e
30 C=int(B*E)
40 D=D+C
41 print Ct,B,C,D
50 if D=prmdiv(D) then print D:stop
55 Ct=Ct+1
60 goto 20

Formula

Multiply consecutive primes by e, take integer, sum until a prime sum is reached.