login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A109068 Products of two successive primes that can be partitioned in sum of three distinct primes which contain the prime divisors. 0
15, 35, 77, 221, 899, 1517, 2021, 5183, 8633, 11663, 23707, 27221, 36863, 41989, 47053, 57599, 60491, 77837, 111547, 164009, 233273, 324899, 372091, 416021, 471953, 522713, 568507, 608351, 665831, 680621 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Largest prime of sum of three primes are primes of the form p*q - p - q, where p and q are two successive primes (A096345).

LINKS

Table of n, a(n) for n=1..30.

FORMULA

a(n) = A096345(n) - A001043(n).

EXAMPLE

a(1) = 15 because 15 = 3+5+7 with 3*5 =15;

a(2) = 35 because 35 = 5+7+23 with 5*7=35;

a(3) = 77 because 77 = 7+11+59 with 7*11=77;

a(4) = 221 because 221= 13+17+191 with 13*17=221

PROG

(PARI) lista(nn) = {for (n=1, nn, p = prime(n); q = prime(n+1); prd = p*q; if (isprime(prd - p - q), print1(prd, ", ")); ); } \\ Michel Marcus, Jun 03 2013

CROSSREFS

Cf. A096345.

Sequence in context: A234542 A242235 A082663 * A238232 A061367 A070161

Adjacent sequences:  A109065 A109066 A109067 * A109069 A109070 A109071

KEYWORD

nonn

AUTHOR

Giovanni Teofilatto, Aug 17 2005

EXTENSIONS

More terms from Michel Marcus, Jun 03 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 9 19:51 EST 2019. Contains 329879 sequences. (Running on oeis4.)