noncontig(n)=n>>=valuation(n,2);n++;n>>=valuation(n,2);n>1;
nonContigSubseq(v)={
  for(i=5,2^#v-1,
    if(noncontig(i),
      print(vecextract(v,i))
    )
  )
};
nonContigSubseq([1,2,3])
nonContigSubseq(["a","b","c","d","e"])