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%I #7 Feb 06 2021 04:54:15
%S 0,1,9,46,111,204,750,1089,1350,2301,3075,3504,4200,5500,6069,10071,
%T 10450,10836,12036,12450,15081,16014,19500,20026,20559,21099,22200,
%U 23904,25075,27501,30039,30691,31350,32016,34056,34750,39061,39804,40554,42075,44409,45201
%N Enneagonal numbers for which the product of the digits is also an enneagonal number.
%H Amiram Eldar, <a href="/A117052/b117052.txt">Table of n, a(n) for n = 1..10000</a>
%e 46 is in the sequence because (1) it is an enneagonal number and (2) the product of its digits 4*6 = 24 is also an enneagonal number.
%t pod[n_] := Times @@ IntegerDigits[n]; ennQ[n_] := n == 0 || IntegerQ[(Sqrt[56*n + 25] + 5)/14]; Select[Table[n*(7*n - 5)/2, {n, 0, 120}], ennQ[pod[#]] &] (* _Amiram Eldar_, Feb 06 2021 *)
%Y Cf. A001106, A007954.
%K base,nonn
%O 1,3
%A Luc Stevens (lms022(AT)yahoo.com), Apr 15 2006
%E Offset corrected by _Amiram Eldar_, Feb 06 2021
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