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!)
 A152871 Irregular table with first row containing the single term 3; in the n-th row, n>=2, we list in increasing order those d=2^(n+1)-a, for each term a in all the preceding rows, such that d is prime. 2
 3, 5, 11, 13, 19, 29, 53, 59, 61, 67, 109, 197, 227, 251, 499, 509, 773, 797, 827, 971, 1013, 1019, 1021, 1549, 1987, 2029, 3083, 3299, 3323, 4091, 4093, 4099, 6163, 8179, 15413, 16187, 16381, 28669, 30781, 31219, 32707, 32749, 50123, 62213, 64709, 64763 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Since primes above the n-th row are <2^n, primes in the n-th row are >2^(n+1)-2^n=2^n. Thus in different rows primes are different. Questions: 1) Is every row nonempty? 2) Is the sequence infinite (an infinite number of nonempty rows)? LINKS Jason Kimberley, Table of n, a(n) for n = 1..1016 EXAMPLE 1: 3; 2: 5; 3: 11, 13; 4: 19, 29; 5: 53, 59, 61; 6: 67, 109; 7: 197, 227, 251; 8: 499, 509; 9: 773, 797, 827, 971, 1013, 1019, 1021; PROG (MAGMA) A152871and2 :=     function(N)         A := [[3]]; C := [1];         for n in [2..N] do             C[n] := 0;             A[n] := [];             for a in Reverse(&cat A) do                 d := 2^(n+1) - a;                 if                     IsPrime(d)                 then                     Append(~A[n], d);                     C[n] +:= 1;                 end if;             end for;         end for;         return A, C;     end function; A152871and2(20); CROSSREFS The n-th row has length A152872(n). Cf. A152451. Sequence in context: A003629 A175865 A001122 * A329760 A156221 A207325 Adjacent sequences:  A152868 A152869 A152870 * A152872 A152873 A152874 KEYWORD nonn,easy,tabf AUTHOR Vladimir Shevelev, Dec 14 2008 EXTENSIONS Heavily edited by Jason Kimberley, Feb 12 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.

Last modified April 15 02:27 EDT 2021. Contains 342974 sequences. (Running on oeis4.)