A222311 Leading diagonal of triangle in A222310.

1, 2, 3, 6, 5, 15, 105, 70, 1, 5, 33, 55, 65, 273, 1001, 1430, 17, 17, 969, 4845, 1785, 6545, 37145, 81719, 17, 1105, 3553, 969969, 672945, 81345, 955049953, 66786710, 33, 561, 385, 6545, 6105, 657305, 15873, 8544965, 1353, 268345, 61705, 329681, 650793, 24173705985, 3065857, 250538768183, 561, 33, 21945

Offset

1,2

Comments

See A222313 for the numbers that appear in this sequence.

Links

N. J. A. Sloane, Table of n, a(n) for n = 1..500

C. Cobeli and A. Zaharescu, Promenade around Pascal Triangle-Number Motives, Bull. Math. Soc. Sci. Math. Roumanie, Tome 56(104) No. 1, 2013, 73-98.

Cristian Cobeli, Alexandru Zaharescu, A game with divisors and absolute differences of exponents, arXiv:1411.1334 [math.NT], 2014 (see page 12).

Cristian Cobeli, Mihai Prunescu, Alexandru Zaharescu, A growth model based on the arithmetic Z-game, arXiv:1511.04315 [math.NT], 2015.

Mathematica

Join[r = {1}, Table[Reverse[r = FoldList[#1*#2/GCD[#1, #2]^2&, n, r]], {n, 2, 100}][[All, 1]]] (* Jean-François Alcover, Sep 04 2018, after Ivan Neretin in A222310 *)

Crossrefs

Cf. A222310, A222313.

Sequence in context: A358170 A098012 A066117 * A156833 A367370 A345129

Adjacent sequences: A222308 A222309 A222310 * A222312 A222313 A222314

Keyword

nonn

Author

N. J. A. Sloane, Feb 16 2013

Status

approved