The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A246824 Numbers k for which A242720(k) = (prime(k)+1)^2 + 2. 6
 3, 35, 41, 52, 57, 81, 104, 209, 215, 343, 373, 398, 473, 477, 584, 628, 768, 774, 828, 872, 1117, 1145, 1189, 1287, 1324, 1435, 1615, 1634, 1653, 1704, 1886, 1925, 2070, 2075, 2123, 2171, 2193, 2425, 2449, 2605, 2633, 2934, 2948, 3019, 3194, 3273, 3533, 3552, 3685, 3758 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS By a comment in A246748, A242720(k) >= (prime(k)+1)^2 + 2, and equality is attained in this sequence. Prime(a(n)) >= 5 and is in the intersection of A001359 and A157468. LINKS Chai Wah Wu, Table of n, a(n) for n = 1..10000 MATHEMATICA lpf[n_] := FactorInteger[n][[1, 1]]; aQ[n_] := Module[{k=6}, While[PrimeQ[k-3] && PrimeQ[k-1] || lpf[k-1]<=lpf[k-3] || lpf[k-3] min(factorint(b**2-1)) >= b-1))] # Chai Wah Wu, Jun 03 2019 CROSSREFS Cf. A001359, A157468, A242719, A242720, A246748, A246819, A246821. Sequence in context: A214854 A054287 A176761 * A334068 A001539 A113854 Adjacent sequences:  A246821 A246822 A246823 * A246825 A246826 A246827 KEYWORD nonn AUTHOR Vladimir Shevelev, Sep 04 2014 EXTENSIONS a(40)-a(50) from b-file by Robert Price, Sep 08 2019 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 September 28 13:24 EDT 2020. Contains 337393 sequences. (Running on oeis4.)