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A238969 Degree of divisor lattice in divisor lattice in canonical order. 2
0, 1, 2, 2, 2, 3, 3, 2, 3, 4, 4, 4, 2, 3, 4, 4, 5, 5, 5, 2, 3, 4, 4, 4, 5, 5, 6, 6, 6, 6, 2, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 7, 2, 3, 4, 4, 4, 5, 5, 4, 5, 6, 6, 6, 6, 6, 7, 7, 7, 8, 8, 8, 8, 8, 2, 3, 4, 4, 4, 5, 5, 4, 5, 6, 6, 6, 5, 6, 6, 7, 7, 7, 6, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 9 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..2713 (rows 0..20)

S.-H. Cha, E. G. DuCasse, and L. V. Quintas, Graph Invariants Based on the Divides Relation and Ordered by Prime Signatures, arxiv:1405.5283 [math.NT], 2014.

FORMULA

T(n,k) = A238949(A063008(n,k)). - Andrew Howroyd, Mar 26 2020

EXAMPLE

Triangle T(n,k) begins:

  0;

  1;

  2, 2;

  2, 3, 3;

  2, 3, 4, 4, 4;

  2, 3, 4, 4, 5, 5, 5;

  2, 3, 4, 4, 4, 5, 5, 6, 6, 6, 6;

  ...

PROG

(PARI)

C(sig)={sum(i=1, #sig, if(sig[i]>1, 2, 1))}

Row(n)={apply(C, vecsort([Vecrev(p) | p<-partitions(n)], , 4))}

{ for(n=0, 8, print(Row(n))) } \\ Andrew Howroyd, Mar 26 2020

CROSSREFS

Cf. A238956 in canonical order.

Cf. A063008, A238949.

Sequence in context: A077774 A344150 A128219 * A238956 A331415 A295511

Adjacent sequences:  A238966 A238967 A238968 * A238970 A238971 A238972

KEYWORD

nonn,tabf

AUTHOR

Sung-Hyuk Cha, Mar 07 2014

EXTENSIONS

Offset changed and terms a(50) and beyond from Andrew Howroyd, Mar 26 2020

STATUS

approved

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Last modified July 29 06:21 EDT 2021. Contains 346340 sequences. (Running on oeis4.)