

A335572


Irregular triangle whose row n is the set of numbers d+n/d where d is a divisor of n.


1



2, 3, 4, 4, 5, 6, 5, 7, 8, 6, 9, 6, 10, 7, 11, 12, 7, 8, 13, 14, 9, 15, 8, 16, 8, 10, 17, 18, 9, 11, 19, 20, 9, 12, 21, 10, 22, 13, 23, 24, 10, 11, 14, 25, 10, 26, 15, 27, 12, 28, 11, 16, 29, 30, 11, 13, 17, 31, 32, 12, 18, 33, 14, 34, 19, 35, 12, 36, 12, 13, 15, 20, 37
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OFFSET

1,1


COMMENTS

The last term of row n is n+1.


LINKS

Michel Marcus, Rows n=1..4000 of triangle, flattened


EXAMPLE

Triangle begins:
[2]
[3]
[4]
[4, 5]
[6]
[5, 7]
[8]
[6, 9]
[6, 10]
[7, 11]
...


MATHEMATICA

Table[Map[# + n/# &, #[[Ceiling[Length[#]/2] ;; 1 ]] ] &@ Divisors[n], {n, 36}] // Flatten (* Michael De Vlieger, Jan 27 2021 *)


PROG

(PARI) row(n) = my(d=divisors(n)); Set(vector(#d, k, d[k]+n/d[k]));


CROSSREFS

Cf. A027750 (divisors of n), A038548 (row lengths), A063655 (1st column).
Sequence in context: A248110 A108872 A147847 * A268680 A126974 A089058
Adjacent sequences: A335569 A335570 A335571 * A335573 A335574 A335575


KEYWORD

nonn,tabf


AUTHOR

Michel Marcus, Jan 26 2021


STATUS

approved



