COMMENT FROM M. F. Hasler RE A037916

[Maximilian Hasler]

%I A037916
%S A037916 0,1,1,2,1,11,1,3,2,11,1,21,1,11,11,4,1,12,1,21,11,11,1,31,2,11,3,21,1
%C A037916 The sequence of (nonzero) exponents in the prime
factorization of a number is called its prime signature.
%H A037916 Wikipedia, <a href="http://en.wikipedia.org/wiki/Prime_signature">
   Prime signature</a>.
%o A037916 (PARI) A037916(n)=if( n>1, eval(concat(concat([""],factor(n)[,2]~))))
%o A037916 (PARI) primesig(n)=sum(i=1,#n=factor(n)[,2],10^(#n-i)*n[i])
\\ the same result up to 2^10
%K A037916 nonn,easy
%O A037916 1,4
%A A037916 M. F. Hasler (www.univ-ag.fr/~mhasler), Apr 17 2008