

A358601


Number of genetic relatives of a person M in a genealogical tree extending back n generations and where everyone has 7 children down to the generation of M.


5



1, 9, 109, 1485, 20701, 289629, 4054429, 56761245, 794655901, 11125179549, 155752507549, 2180535093405, 30527491283101, 427384877914269, 5983388290701469, 83767436069623965, 1172744104974342301, 16418417469640005789, 229857844574958508189
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OFFSET

0,2


COMMENTS

M has 2 parents, 4 grandparents, and so on up to 2^n top ancestors at the top of the tree.
The genetic relatives of M are all descendants of those ancestors.
M is a genetic relative of himself or herself.


LINKS



FORMULA

a(n) = 2^n + 7*(14^n  1)/13.


MATHEMATICA

LinearRecurrence[{17, 44, 28}, {1, 9, 109}, 25] (* Paolo Xausa, Feb 09 2024 *)


PROG

(Python) print([2**n+7*(14**n1)//13 for n in range(10)])


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



STATUS

approved



