OFFSET
0,2
COMMENTS
The positive entries are the viabin numbers of integer partitions into even parts. The viabin number of an integer partition is defined in the following way. Consider the southeast border of the Ferrers board of the integer partition and consider the binary number obtained by replacing each east step with 1 and each north step, except the last one, with 0. The corresponding decimal form is, by definition, the viabin number of the given integer partition. "Viabin" is coined from "via binary". For example, consider the integer partition [6,4,4,2]. The southeast border of its Ferrers board yields 110110011, leading to the viabin number 435 (a term of the sequence). - Emeric Deutsch, Sep 11 2017
LINKS
FORMULA
a(n) = 3*A003714(n).
MATHEMATICA
3 Select[Range[300], BitAnd[#, 2 #]==0 &] (* Vincenzo Librandi, Sep 12 2017 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Oct 18 2016
STATUS
approved