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.

A137355 Slowest-increasing sequence of noncomposite numbers such that the partial sums of the sequence are perfect powers.

Original entry on oeis.org

1, 3, 5, 7, 11, 37, 61, 71, 11971, 16057, 40697, 46679, 61547, 66889, 177839, 192781, 355643, 407977, 1082099, 1096621, 1100467, 1102537, 3369329, 3402271, 4442993, 4462307, 5293999, 5304701, 7099793, 7104607, 7342633, 7413467, 9448897, 9657503
Offset: 1

Views

Author

R. J. Mathar, Mar 07 2008

Keywords

Comments

Also the first differences of A137354.

Crossrefs

Programs

  • Mathematica
    fQ[n_] := GCD @@ Last /@ FactorInteger@n > 1; p = 3; sp = 2; lst = {2}; While[p < 10^9, If[ fQ[sp + p], AppendTo[lst, p]; Print@p; sp = sp + p]; p = NextPrime@p]; lst

Extensions

Edited and extended by Robert G. Wilson v, Apr 20 2010

A174722 Slowest increasing sequence of odd primes such that the partial sums of the sequence from the second on are perfect powers.

Original entry on oeis.org

3, 5, 17, 103, 233, 1367, 1753, 2351, 7393, 19543, 20593, 46639, 54449, 284527, 344249, 407791, 512009, 812431, 844433, 1214407, 1316033, 2109671, 2233601, 11251351, 11267777, 13903271, 14449489, 16203287, 16451713, 18219679, 18367721, 18529111
Offset: 1

Views

Author

Giovanni Teofilatto, Mar 28 2010

Keywords

Examples

			3+5=8, 3+5+17=25, 3+5+17+103=128 are perfect powers, i.e., in A007504.
		

Crossrefs

Programs

  • Mathematica
    fQ[n_] := GCD @@ Last /@ FactorInteger@n > 1; p = sp = 3; lst = {3}; While[p < 10^9, If[ fQ[sp + p], AppendTo[lst, p]; Print@p; sp = sp + p]; p = NextPrime@p]; lst

Extensions

Edited and extended by R. J. Mathar, Mar 31 2010
Edited, corrected and extended by Robert G. Wilson v, Apr 20 2010
Showing 1-2 of 2 results.