A056602 Numbers A such that there is an equation of the form (A = Product of m + 1 primes) = (B = Product of m primes) + (C = Product of m primes), where A*B*C is a primorial number (A002110).

10, 231, 2958, 226083

Offset

1,1

Comments

Terms have been verified. There are no additional terms for m <= 7. - Rick L. Shepherd, Jun 16 2008

(C(3m+1,m+1)*C(2m,m))/(C(3m-2,m)*C(2m-2,m-1)) = (27m^2-1)/(m^2+1), so for a brute-force search for large m, about 27 times as many cases must be examined for m as for m-1. - Rick L. Shepherd, Jun 16 2008

Links

Table of n, a(n) for n=1..4.

Example

10 = (2*5) = 3+7;
231 = (3*7*11) = (2*5)+(13*17);
2958 = (2*3*17*29) = (5*13*23)+(7*11*19);
226083 = (3*11*13*17*31) = (2*7*19*23)+(5*29*37*41).

Crossrefs

Cf. A057035, A056600, A002110.

Sequence in context: A276019 A004702 A027952 * A349731 A239772 A239773

Adjacent sequences: A056599 A056600 A056601 * A056603 A056604 A056605

Keyword

more,nonn

Author

Naohiro Nomoto, Aug 21 2000

Status

approved