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.

A203076 Convert A203075(n) to base 10.

Original entry on oeis.org

0, 1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 18, 19, 21, 22, 23, 26, 27, 29, 30, 31, 39, 42, 43, 45, 46, 47, 49, 50, 51, 53, 54, 55, 58, 59, 61, 62, 63, 67, 69, 70, 71, 74, 75, 77, 78, 79, 81, 82, 83, 85, 86, 87, 90, 91, 93, 94, 95
Offset: 0

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Author

Frank M Jackson and N. J. A. Sloane, Dec 28 2011

Keywords

Comments

Any nonnegative number can be written as a sum of distinct terms of the complete sequence, A203074. Terms a(n) are decimal representations of binary vectors (in ascending powers of 2) used to select terms of A203074 that when summed give n.

Crossrefs

Programs

  • Mathematica
    nextprime[n_Integer] := (k=n+1;While[!PrimeQ[k], k++];k);aprime[m_Integer] := (If[m==0, 1, nextprime[2^(m-1)]]);seqtable[l_] := (stable=Table[aprime[j], {j, 0, l}];stable);inttable[p_] := (itable=Reverse[IntegerDigits[p, 2]];itable);h=1;otable={0};ttable={};While[h<100, (inttable[h];seqtable[Length[itable]-1];test=itable.stable;If[!MemberQ[ttable, test], AppendTo[otable, h], Null];AppendTo[ttable, test];h++)];otable

Formula

Binary(a(n)) x A203074 = n, where x is the inner product and the binary vector is in ascending powers of 2 with infinite trailing zeros.