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.

A281257 Primes in A067894: primes in the partial sums of the binary representations of the first m natural numbers, reading these representations in decimal.

Original entry on oeis.org

11, 223, 2556997, 3333331, 14559007, 47836783, 56672227, 65555671, 181114559, 411488881, 583227779, 1399999987, 5723503439, 10047846871, 11361255547, 13787777879, 18474111311, 19905449987, 20235780199, 21226777753, 22557892319, 71445725647, 83447001413, 103459003423
Offset: 1

Views

Author

K. D. Bajpai, Jan 18 2017

Keywords

Comments

Intersection of A000040 and A067894.

Examples

			0 + 1 + 10 = 11 (prime), so 11 is in the sequence.
0 + 1 + 10 + 11 + 100 + 101 = 223 (prime), so 223 is in the sequence.
		

Crossrefs

Programs

  • Maple
    select(isprime, ListTools:-PartialSums(map(convert,[$1..1000],binary))); # Robert Israel, Jan 18 2017
  • Mathematica
    Select[Accumulate[Table[FromDigits[IntegerDigits[n, 2]], {n, 0, 1000}]], PrimeQ]
  • PARI
    F(k,{b=10})=sum(i=1,k,subst(Pol(binary(i),y),y,b));
    test(k,{b=10})={my(z=F(k,b));return(isprime(z)*z)};
    Values(n,{b=10})={my(L=List(),j,t);while(#LR. J. Cano, Jan 19 2017