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 1-3 of 3 results.

A224610 Smallest j such that j*2*prime(n)^3-1 and j*2*prime(n)*q^2-1 are prime.

Original entry on oeis.org

2, 2, 5, 7, 59, 142, 264, 25, 8, 21, 124, 33, 60, 87, 9, 231, 5, 6, 82, 155, 7, 66, 72, 21, 42, 105, 15, 48, 250, 68, 222, 54, 47, 195, 255, 360, 205, 6, 83, 26, 5, 1, 50, 220, 173, 1, 976, 30, 228, 130, 30, 129, 46, 1106, 65, 62, 15, 109, 24, 41, 922, 15, 132, 89
Offset: 1

Views

Author

Pierre CAMI, Apr 12 2013

Keywords

Links

Crossrefs

Cf. A224490, A224609, A224611, A224612.

Programs

  • Mathematica
    a[n_] := For[p = Prime[n]; j = 1, j < 10^6, j++, If[PrimeQ[q = j*2*p^3 - 1] && PrimeQ[j*p*2*q^2 - 1], Return[j]]]; Table[a[n], {n, 1, 75}] (* Jean-François Alcover, Apr 22 2013 *)

A224611 Smallest j such that j*2*p(n)^3-1=q is prime, j*2*p(n)*q^2-1=r, j*2*p(n)*r^2-1=s, where r and s are also prime.

Original entry on oeis.org

902, 145, 771, 1060, 3569, 520, 938, 294, 2457, 3911, 1650, 483, 8604, 3450, 2345, 548, 25004, 1635, 5767, 14519, 2518, 6394, 198, 7961, 4272, 8370, 4146, 654, 4489, 6987, 222, 5426, 5250, 17670, 7691, 360, 3994, 20821, 9008, 6525, 9204, 1464, 6111, 6625, 11229, 3315, 62340, 735, 6962, 5236
Offset: 1

Views

Author

Pierre CAMI, Apr 12 2013

Keywords

Links

Crossrefs

Cf. A224491, A224609, A224610, A224612.

Programs

  • Mathematica
    a[n_] := For[j = 1, j < 10^7, j++, p = Prime[n]; If[PrimeQ[q = j*2*p^3 - 1] && PrimeQ[r = j*2*p*q^2 - 1] && PrimeQ[j*2*p*r^2 - 1], Return[j]]]; Table[ Print[an = a[n]]; an, {n, 1, 50}] (* Jean-François Alcover, Apr 12 2013 *)

A224627 Prime numbers p such that 2*p^3-1, 2*p*q^2-1, 2*p*r^2-1, and 2*p*s^2-1 are prime numbers.

Original entry on oeis.org

19460899, 86276401, 87980803, 167646631, 300722029, 343507111, 479516311, 906597943, 998757829, 1031308249, 1112697199, 1311383431, 1962194053
Offset: 1

Views

Author

Pierre CAMI, Apr 12 2013

Keywords

Comments

Subsequence of A224612, p = prime(n) when A224612(n)=1.

Crossrefs

Cf. A224612, A224613, A224614, A224626.

Programs

  • Mathematica
    Reap[ For[p = 2, p < 2*10^9, p = NextPrime[p], If[PrimeQ[q = 2*p^3 - 1] && PrimeQ[r = 2*p*q^2 - 1] && PrimeQ[s = 2*p*r^2 - 1] && PrimeQ[2*p*s^2 - 1], Print[p]; Sow[p]] ]][[2, 1]] (* Jean-François Alcover, Apr 22 2013 *)

Extensions

More terms from Jean-François Alcover, Apr 22 2013
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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