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.

A239282 a(n) = A045917(n)*prime(n).

Original entry on oeis.org

0, 3, 5, 7, 22, 13, 34, 38, 46, 58, 93, 111, 123, 86, 141, 106, 236, 244, 134, 213, 292, 237, 332, 445, 388, 303, 515, 321, 436, 678, 381, 655, 822, 278, 745, 906, 785, 815, 1169, 692, 895, 1448, 955, 772, 1773, 796, 1055, 1561, 681, 1374, 1864, 1195, 1446, 2008
Offset: 1

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Author

Raghavendra Ugare, Mar 14 2014

Keywords

Crossrefs

Programs

  • Mathematica
    (*Returns the various ways a number (presumed to be even) can be split as a sum of 2 Primes.*)
    getGoldBachSplits[n_Integer] := Module[{i, splits = {}, a, b},
      (
       For[i = 1,
        Prime[i] < n,
        i++,
        a = Prime[i] ;
        b = n - Prime[i];
        If[PrimeQ[b],
         If[MemberQ[splits, {b, a}], Null,
          AppendTo[splits, {a, b}]],
         Null];
        ]; (*End For-loop...*)
       splits
       )
      ]
    (* Now we generate our series...*)
    series[n_] :=
    Module[{}, (Table[Prime[i]*Length[getGoldBachSplits[2 i]], {i, 2, n}])]