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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A234096 Integers of the form (p*q + 1)/2, where p and q are distinct primes. 5
8, 11, 17, 18, 20, 26, 28, 29, 33, 35, 39, 43, 44, 46, 47, 48, 56, 58, 60, 62, 65, 67, 71, 72, 73, 78, 80, 81, 89, 92, 93, 94, 101, 102, 103, 105, 107, 108, 109, 110, 111, 118, 119, 124, 125, 127, 130, 133, 134, 144, 146, 148, 150, 151, 152, 153, 155, 160 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..58.

FORMULA

1 + A234093.

EXAMPLE

(3*5 + 1)/2 = 8, (3*7 + 1)/2 = 11.

MATHEMATICA

t = Select[Range[1, 7000, 2], Map[Last, FactorInteger[#]] == Table[1, {2}] &]; Take[(t + 1)/2, 120] (* A234096 *)

v = Flatten[Position[PrimeQ[(t + 1)/2], True]] ; w = Table[t[[v[[n]]]], {n, 1, Length[v]}]  (* A233562 *)

(w + 1)/2 (* A234098 *)    (* Peter J. C. Moses, Dec 23 2013 *)

CROSSREFS

Cf. A234093, A233562, A234098.

Sequence in context: A065348 A155717 A188197 * A111254 A127271 A118549

Adjacent sequences:  A234093 A234094 A234095 * A234097 A234098 A234099

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, Dec 27 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 February 26 12:43 EST 2020. Contains 332280 sequences. (Running on oeis4.)