The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A140365 a(n) = sum of primes in {6*n-5, 6*n-1}. 0
 5, 18, 30, 42, 29, 31, 78, 90, 53, 59, 61, 138, 73, 162, 89, 0, 198, 210, 222, 0, 0, 258, 137, 139, 149, 151, 157, 330, 173, 179, 181, 191, 390, 199, 0, 211, 0, 450, 462, 239, 241, 251, 257, 263, 269, 271, 558, 283, 293, 0, 0, 618, 630, 0, 0, 331, 337, 347, 702 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..59. FORMULA a(n) = (6n-5)*isprime(6n-5) + (6n-1)*isprime(6n-1), where isprime = A010051. - M. F. Hasler, Jun 15 2008 EXAMPLE 6*11 - 5 = 61 is prime, but 6*11 - 1 = 65 is not prime, so a(11) = 61. MAPLE a:= n-> add(i, i=select(isprime, [6*n-5, 6*n-1])): seq(a(n), n=1..59); # Alois P. Heinz, May 18 2021 PROG (PARI) a(n)=(6*n-5)*isprime(6*n-5)+(6*n-1)*isprime(6*n-1) \\ M. F. Hasler, Jun 15 2008 (Python) from sympy import isprime def a(n): return sum(k*isprime(k) for k in {6*n-5, 6*n-1}) print([a(n) for n in range(1, 60)]) # Michael S. Branicky, May 18 2021 CROSSREFS Cf. A002476, A007528. Sequence in context: A155450 A322409 A287894 * A063294 A063141 A154609 Adjacent sequences: A140362 A140363 A140364 * A140366 A140367 A140368 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, Jun 10 2008 EXTENSIONS Edited by M. F. Hasler, Jun 15 2008 a(52) corrected and a(58) deleted by Michael S. Branicky, May 18 2021 STATUS approved

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

Last modified December 5 21:07 EST 2023. Contains 367594 sequences. (Running on oeis4.)