This site is supported by donations to The OEIS Foundation.

 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!)
 A131101 Numbers that when added it to their prime factors +1 the result is a prime number, member of A131102. 1
 1, 2, 3, 5, 11, 23, 27, 29, 30, 32, 36, 41, 53, 60, 66, 75, 78, 83, 89, 113, 114, 117, 130, 131, 132, 138, 140, 171, 173, 175, 179, 186, 191, 204, 220, 233, 239, 240, 246, 251, 255, 258, 260, 276, 279, 281, 285, 286, 293, 308, 310, 325, 338, 340, 354, 359, 363 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The Sophie Germain prime numbers (A005384) are part of this sequence because when adding to one of them its only prime factor (itself) + 1 = 2*A005384 + 1 the result is another prime number (A005385) LINKS FORMULA a(n)+ prime factors of a(n) + 1 = p ; p is a prime number, member of A131102. EXAMPLE a(8)=29 because 29 + its only prime factor (itself) + 1 = 29+29+1= 59, and 59 is a prime number = A131102(8) = A005385(6). a(9)=30 because 30 + its prime factors + 1 = 30 +(2+3+5)+1 =41, and 41 is a prime number = A131102(9). CROSSREFS Sequence in context: A073880 A118332 A118333 * A188534 A214196 A246857 Adjacent sequences:  A131098 A131099 A131100 * A131102 A131103 A131104 KEYWORD easy,nonn AUTHOR Tomas Xordan, Jun 14 2007 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.

Last modified December 5 17:42 EST 2019. Contains 329768 sequences. (Running on oeis4.)