A182727 Sum of largest parts of the shell model of partitions with n regions.

1, 3, 6, 8, 12, 15, 20, 22, 26, 29, 35, 38, 43, 47, 54, 56, 60, 63, 69, 74, 78, 86, 89, 94, 98, 105, 108, 114, 119, 128, 130, 134, 137, 143, 148, 152, 160, 164, 171, 177, 182, 192, 195, 200, 204, 211, 214, 220, 225, 234, 239, 243, 251, 258, 264, 275, 277, 281

Offset

1,2

Comments

Question: Is there some connection with fractals?

Links

Alois P. Heinz, Table of n, a(n) for n = 1..4000

Omar E. Pol, Illustration of the seven regions of 5

Formula

a(A000041(n)) = A182181(A000041(n) = A006128(n). - Omar E. Pol, May 24 2012

Example

For n = 6 the largest parts of the first six regions of the shell model of partitions are 1, 2, 3, 2, 4, 3, so a(6) = 1+2+3+2+4+3 = 15.
Written as a triangle begins:
1;
3;
6;
8,   12;
15,  20;
22,  26, 29, 35;
38,  43, 47, 54;
56,  60, 63, 69, 74, 78, 86;
89,  94, 98,105,108,114,119,128;
130,134,137,143,148,152,160,164,171,177,182,192;
195,200,204,211,214,220,225,234,239,243,251,258,264,275;

Crossrefs

Partial sums of A141285. Row j has length A187219(j). Right border gives A006128.

Cf. A135010, A141285, A182728, A182729, A186114, A206437, A182181, A182244, A210990.

Sequence in context: A185549 A185597 A082873 * A220001 A310138 A310139

Adjacent sequences: A182724 A182725 A182726 * A182728 A182729 A182730

Keyword

nonn,tabf

Author

Omar E. Pol, Jan 25 2011

Extensions

New name from Omar E. Pol, Apr 26 2012

Status

approved