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 A309123 a(1) = 50 and for any n > 0, a(n+1)^2 is the smallest square that begins with a(n). 2
 50, 71, 267, 517, 2274, 1508, 3884, 1971, 444, 667, 817, 286, 535, 732, 856, 2926, 541, 736, 858, 293, 542, 233, 483, 695, 834, 2888, 16995, 41225, 20304, 4506, 6713, 2591, 5091, 22564, 47502, 21795, 46686, 21607, 46484, 215602, 46433, 68142, 261041, 510922 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This sequence is similar to A308055. The initial value (50) seems to be the first one for which the iteration of A018796 diverges; there are neither duplicates nor squares among the first 79000 terms. LINKS Rémy Sigrist, Table of n, a(n) for n = 1..1000 Rémy Sigrist, PARI program for A309123 FORMULA a(1) = 50 and then a(n+1) = A018796(a(n)) for n > 0. EXAMPLE The first terms, alongside the square of a(n+1), are:   n   a(n)  a(n+1)^2   --  ----  --------    1    50      5041    2    71     71289    3   267    267289    4   517   5171076    5  2274   2274064    6  1508  15085456    7  3884   3884841    8  1971    197136    9   444    444889   10   667    667489   11   817     81796   12   286    286225   13   535    535824   14   732    732736   15   856   8561476   16  2926    292681 PROG (PARI) See Links section. CROSSREFS Cf. A018796, A308055. Sequence in context: A272607 A224552 A039473 * A146170 A217857 A071366 Adjacent sequences:  A309120 A309121 A309122 * A309124 A309125 A309126 KEYWORD nonn,base AUTHOR Rémy Sigrist, Jul 13 2019 STATUS approved

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Last modified November 28 08:12 EST 2021. Contains 349401 sequences. (Running on oeis4.)