A024967 Positions of primes in A003072.

1, 3, 5, 7, 11, 17, 25, 28, 34, 38, 39, 41, 46, 48, 53, 57, 68, 72, 73, 77, 80, 91, 100, 108, 110, 113, 115, 116, 120, 123, 128, 135, 144, 156, 161, 175, 185, 189, 198, 202, 205, 217, 224, 231, 235, 245, 247, 252, 255, 267, 273, 275, 276, 278, 285, 297, 301, 304, 315, 320, 324

Offset

1,2

Links

Robert Israel, Table of n, a(n) for n = 1..8446

Maple

N:= 10000: # for members of A003072 up to N
S:= {}:
for x from 1 while 3*x^3 <= N do
  for y from x while x^3+2*y^3<=N do
    for z from y do
      v:= x^3+y^3+z^3;
      if v > N then break fi;
      S:= S union {v}
od od od:
S:= sort(convert(S, list)):
select(i -> isprime(S[i]), [$1..nops(S)]); # Robert Israel, Aug 27 2019

Crossrefs

Sequence in context: A065557 A266164 A152999 * A135246 A109543 A229168

Adjacent sequences: A024964 A024965 A024966 * A024968 A024969 A024970

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Jul 30 2019

Status

approved