A175490 a(n) = Product_{k=1..n} b(k,n), where b(k,n) is the largest positive integer that, when written in binary, occurs as a substring in both binary k and binary n.

1, 2, 3, 8, 20, 144, 63, 256, 1152, 1600, 118800, 995328, 8424000, 12192768, 178605, 1048576, 8912896, 21233664, 27572576256, 13107200000, 537600000, 2032335360000, 30928035600000, 760840571584512, 13541327555788800

Offset

1,2

Comments

Row products of A175488. - R. J. Mathar, Sep 28 2010

Links

Rémy Sigrist, Table of n, a(n) for n = 1..819

Rémy Sigrist, PARI program for A175490

Maple

A175488 := proc(n, m) for a from m to 1 by -1 do abin := convert(a, base, 2) ; nbin := convert(n, base, 2) ; mbin := convert(m, base, 2) ; if verify(abin, nbin, 'sublist') and verify(abin, mbin, 'sublist') then return a; end if; end do: end proc:
A175490 := proc(n) mul(A175488(n, m), m=1..n) ; end proc:
seq(A175490(n), n=1..30) ;
# R. J. Mathar, Sep 28 2010

Prog

(PARI) See Links section.

Crossrefs

Cf. A175488, A175489.

Sequence in context: A066051 A056971 A108125 * A118854 A192151 A137652

Adjacent sequences: A175487 A175488 A175489 * A175491 A175492 A175493

Keyword

base,nonn

Author

Leroy Quet, May 28 2010

Extensions

More terms from R. J. Mathar, Sep 28 2010

Status

approved