

A358600


Number of genetic relatives of a person M in a genealogical tree extending back n generations and where everyone has 6 children down to the generation of M.


4



1, 8, 82, 950, 11326, 135758, 1628782, 19544750, 234535726, 2814426158, 33773108782, 405277295150, 4863327521326, 58359930214958, 700319162497582, 8403829949807150, 100845959397358126, 1210151512767642158, 14521818153210395182, 174261817838522120750
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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

Table of n, a(n) for n=0..19.
Hans Braxmeier, Calculating the number of genetic relative people in a genealogical tree.
Index entries for linear recurrences with constant coefficients, signature (15,38,24).


FORMULA

a(n) = 2^n + 6*(12^n  1)/11.
G.f.: (1  7*x)/((1  x)*(1  2*x)*(1  12*x)).  Stefano Spezia, Dec 05 2022


MATHEMATICA

LinearRecurrence[{15, 38, 24}, {1, 8, 82}, 20] (* Hugo Pfoertner, Dec 05 2022 *)


PROG

(Python) print([2**n+6*(12**n1)//11 for n in range(10)])


CROSSREFS

Other numbers of children: A076024 (2), A358504 (3), A358598 (4), A358599 (5), A358601 (7).
Sequence in context: A249898 A073699 A356829 * A163191 A241708 A317119
Adjacent sequences: A358592 A358598 A358599 * A358601 A358602 A358603


KEYWORD

nonn,easy


AUTHOR

Hans Braxmeier, Nov 23 2022


STATUS

approved



