The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A001480 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A001480

Let p = A007645(n) be the n-th generalized cuban prime and write p = x^2 + 3*y^2; a(n) = y.
(history; published version)

#36 by Charles R Greathouse IV at Tue Feb 07 11:40:27 EST 2017

STATUS

editing

approved

#35 by Charles R Greathouse IV at Tue Feb 07 11:40:24 EST 2017

PROG

(PARI) do(lim)=my(v=List(), q=Qfb(1, 0, 3)); forprime(p=2, lim, if(p%3==2, next); listput(v, qfbsolve(q, p)[2])); Vec(v) \\ Charles R Greathouse IV, Feb 07 2017

STATUS

approved

editing

#34 by Jon E. Schoenfield at Mon Dec 26 01:54:02 EST 2016

STATUS

editing

approved

#33 by Jon E. Schoenfield at Mon Dec 26 01:54:00 EST 2016

LINKS

T. D. Noe, <a href="/A001480/b001480.txt">Table of n, a(n) for n = 1..1000</a>

AUTHOR

N. J. A. Sloane.

STATUS

approved

editing

#32 by N. J. A. Sloane at Sun Aug 02 20:21:00 EDT 2015

STATUS

editing

approved

#31 by N. J. A. Sloane at Sun Aug 02 20:20:57 EDT 2015

LINKS

A. J. C. Cunningham, <a href="/A002330/a002330.pdf">Quadratic Partitions</a>, Hodgson, London, 1904 [Annotated scans of selected pages]

STATUS

approved

editing

#30 by N. J. A. Sloane at Fri Jun 19 17:00:00 EDT 2015

STATUS

editing

approved

#29 by N. J. A. Sloane at Fri Jun 19 16:59:57 EDT 2015

REFERENCES

B. van der Pol and P. Speziali, The primes in k(prho). Nederl. Akad. Wetensch. Proc. Ser. A. {54} = Indagationes Math. 13, (1951). 9-15 (1 plate).

LINKS

B. van der Pol and P. Speziali, <a href="/A001479/a001479.pdf">The primes in k(rho)</a> (annotated and scanned copy)

STATUS

approved

editing

#28 by Charles R Greathouse IV at Thu Nov 21 13:11:11 EST 2013

MATHEMATICA

nmax = 63; nextCuban[p_] := If[p1 = NextPrime[p]; Mod[p1, 3] > 1, nextCuban[p1], p1]; cubanPrimes = NestList[ nextCuban, 3, nmax ]; f[p_] := y /. ToRules[ Reduce[x > 0 && y > 0 && p == x^2 + 3*y^2, {x, y}, Integers]]; a[1] = 1; a[n_] := f[cubanPrimes[[n]]]; Table[ a[n] , {n, 1, nmax}] (* From _Jean-François Alcover, _, Oct 19 2011 *)

Discussion

Thu Nov 21

13:11

OEIS Server: https://oeis.org/edit/global/2066

#27 by Reinhard Zumkeller at Thu Jul 11 10:36:55 EDT 2013

STATUS

editing

approved