cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A140250 a(n) is the largest cube <= A066525(n).

Original entry on oeis.org

343, 15625, 34965783, 106496424, 3023464536, 3659383421, 7222633237, 10403062487, 11179320256, 11993263569, 25881801912, 36495256013, 40672093519, 47516597848, 49917330568, 63616767488, 84200449887, 96323848704, 573234910443, 972947676429
Offset: 1

Views

Author

Enoch Haga, May 15 2008

Keywords

Comments

Suggested by Carlos Rivera's Prime Puzzles & Problems Connection, Puzzle 443 (which asks if a sum of consecutive cubes can be a cube or a prime cube).

Examples

			In A066525 the first term is 503, the sum of cubes of the first four consecutive primes, 2 3 5 7. The cube just less than 503 is 343, a(1) in this sequence.
		

Crossrefs

Programs

  • Maple
    with(numtheory): P:=proc(n) add(ithprime(k)^3,k=1..n): end:
    A098563 := proc(n)local m: option remember: if(n=0)then return 0: fi: m:=procname(n-1)+2: while true do if(isprime(P(m)))then return m:fi: m:=m+2:od: end:
    A140250 := proc(n)return floor(surd(P(A098563(n)),3))^3: end:
    seq(A140250(n),n=1..20); # Nathaniel Johnston, Apr 21 2011
  • Mathematica
    Floor[CubeRoot[#]]^3&/@Select[Accumulate[Prime[Range[400]]^3],PrimeQ] (* Harvey P. Dale, May 22 2023 *)

Extensions

Edited by N. J. A. Sloane, Aug 25 2008
a(11)-a(20) from Nathaniel Johnston, Apr 21 2011

A140597 Squares nearest to and > terms in A098562.

Original entry on oeis.org

16, 20736, 76176, 239121, 2211169, 3583449, 29203216, 40005625, 45454564, 55606849, 77299264, 108097609, 115004176, 155650576, 226231681, 302934025, 324684361, 519703209, 551357361, 618367689, 797045824, 944025625, 1039740025
Offset: 1

Views

Author

Enoch Haga, May 17 2008

Keywords

Examples

			The first term of A098562 is 13, the prime sum of 2^2 + 3^2, where 4+9=13. The square just exceeding 13 is 16, the first term of this sequence.
		

Crossrefs

Formula

a(n) = A048761(A098562(n)). - Jason Yuen, Sep 30 2024
Showing 1-2 of 2 results.