This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A080187 Primes p such that 11 is the largest of all prime factors of the numbers between p and the next prime (cf. A052248). 1
 19, 97, 197, 461, 659, 1319, 1451, 2111, 2309, 2969, 3167, 3299, 4157, 5279, 7127, 9239, 10889, 11549, 15971, 16631, 22637, 25409, 26729, 29567, 30491, 34649, 34847, 55439, 55901, 64151, 87119, 92399, 98009, 110879, 118799, 152459, 164999, 176417 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The sequence appears to consist of 19, 97 and the lesser of twin primes q (A001359) such that q+1 is 11-smooth (A051038) but not 7-smooth (A002473, A080195). LINKS EXAMPLE 97 is a term since 98 = 2*7^2, 99 = 3^2*11, 100 = 2^2*5^2 are the numbers between 97 and the next prime 101; 461 is a term since 462 = 2*3*7*11 is the only number between 461 and the next prime 463. PROG (PARI) {forprime(p=2, 180000, q=nextprime(p+1); m=0; j=p+1; while(j

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