A230765 Length of chunks of odd digits, delimited by an even digit, in the concatenation of all terms; smallest such sequence without duplicate terms.
3, 1, 2, 4, 5, 6, 7, 9, 10, 11, 13, 8, 15, 17, 12, 19, 31, 33, 21, 35, 37, 39, 14, 51, 53, 55, 57, 16, 59, 71, 73, 75, 77, 23, 79, 91, 93, 95, 97, 18, 99, 111, 110, 113, 115, 117, 119, 112, 131, 133, 135, 137, 139, 30, 151, 153, 155, 114, 157
Offset: 1
Links
- E. Angelini, Cut the sequence after it's odd/even digits, SeqFan List, Oct 29 2013
Crossrefs
See A230764 for the "even" version.
Programs
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PARI
A230765_vec(n, a=[], s=[],u=0)={my(check(a, s)=my(L=0, j=1); !for(i=1, #s, ( i>L+a[j] || (( i==L+a[j] )== bittest(s[i],0))) && return; bittest(s[i],0) && next; L=i; j++)); check(a, s)||return; n-- || return(a); my(t); for(k=1, 9e9, bittest(u,k)&&next; (t=A230765_vec(n, concat(a, k), concat(s, digits(k)), u+2^k))&& return(t))}