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Numbers k such that A342604(k) is prime.
3

%I #9 Mar 17 2021 13:25:21

%S 1,2,4,14,20,26,31,39,42,57,64,69,87,92,114,127,150,152,172,213,274,

%T 301,326,379,436,460,499,523,597,708,747,817,819,912,1382,1452,1595,

%U 1600,1603,1632,1647,1670,1768,1833,1834,1873,1890,1986,2137,2696,2702,2859,3080,3154,3167,3173,3386,3933

%N Numbers k such that A342604(k) is prime.

%H Robert Israel, <a href="/A342605/b342605.txt">Table of n, a(n) for n = 1..1000</a>

%F A342604(a(n)) = A342606(n).

%e a(3) = 4 is a term because A342604(4) = 17 is prime.

%p p:= 1: R:= NULL:

%p for n from 0 to 14 do

%p for k from 0 to n do

%p p:= nextprime(p);

%p R:= R, binomial(n,k)*p

%p od od:

%p S:= ListTools:-PartialSums([R]):

%p select(t -> isprime(S[t]), [$1..nops(S)]);

%Y Cf. A342604, A342606.

%K nonn

%O 1,2

%A _J. M. Bergot_ and _Robert Israel_, Mar 16 2021