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A340389 Number at the apex of Recamán's triangle of primes and squares with n rows.

%I A340389 #49 Oct 04 2021 21:43:21
%S A340389 0,3,9,59,1669,147456,60924257
%N A340389 Number at the apex of Recamán's triangle of primes and squares with n rows.
%C A340389 Form a triangle of n rows and place a distinct prime or square at each position such that (apart from the bottom row) every number is the sum of the two numbers below it, and such that the number at the apex is as small as possible.
%D A340389 Bernardo Recamán, The Bogotá Puzzles, Dover Publications, 2020, Puzzle 3, p. 3.
%H A340389 M. F. Hasler, <a href="https://oeis.org/wiki/User:M._F._Hasler/A340389">A340389: Notes and PARI program</a>, OEIS wiki, Aug 2021.
%H A340389 M. F. Hasler, <a href="/A340389/a340389.txt">PARI code for A340389</a> (extracted from the above wiki page), Aug 16 2021.
%H A340389 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a340/A340389.java">Java program</a> (github)
%e A340389 n=3:
%e A340389     9
%e A340389    4 5
%e A340389   1 3 2
%e A340389 .
%e A340389 n=4:
%e A340389         59
%e A340389       23  36
%e A340389     16   7  29
%e A340389   13   3   4  25
%e A340389 .
%e A340389 n=5 (B. Mehta):
%e A340389              1669
%e A340389            576  1093
%e A340389         383   193   900
%e A340389      347    36   157   743
%e A340389   324    23    13   144   599
%e A340389 .
%e A340389 n=6 (_Sean A. Irvine): _
%e A340389                      147456
%e A340389                   63487   83969
%e A340389               33211   30276   53693
%e A340389           17424   15787   14489   39204
%e A340389       10853    6571    9216    5273   33931
%e A340389   10529     324    6247    2969    2304   31627
%e A340389 .
%e A340389 From _Bert Dobbelaere_, May 11 2021: (Start)
%e A340389 n=7:
%e A340389                              60924257
%e A340389                         21861757  39062500
%e A340389                     7799257  14062500  25000000
%e A340389                2736757   5062500   9000000  16000000
%e A340389            914257   1822500   3240000   5760000  10240000
%e A340389       258157    656100   1166400   2073600   3686400   6553600
%e A340389   21961    236196    419904    746496   1327104   2359296   4194304
%e A340389 (End)
%o A340389 (PARI) see LINKS
%Y A340389 Cf. A089237 (primes and squares).
%K A340389 nonn,hard,more
%O A340389 1,2
%A A340389 _Sean A. Irvine_, Apr 24 2021
%E A340389 a(7) from _Bert Dobbelaere_, May 11 2021