A004163 Pentagonal numbers written backwards.

0, 1, 5, 21, 22, 53, 15, 7, 29, 711, 541, 671, 12, 742, 782, 33, 673, 524, 774, 235, 95, 156, 517, 287, 258, 529, 1001, 801, 2611, 7421, 5331, 6241, 251, 7161, 7171, 281, 6291, 5302, 7412, 2622, 832, 1052, 5262, 2572, 2882, 5103, 1513, 923, 2343, 7753, 5273

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..10000

Formula

a(n) = A004086(A000326(n)). - Michel Marcus, Apr 05 2014

Maple

a:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||(n*(3*n-1)/2)):
seq(a(n), n=0..50);  # Alois P. Heinz, Apr 09 2015

Crossrefs

Cf. A000326.

Sequence in context: A263130 A165204 A043053 * A350328 A113410 A099654

Adjacent sequences: A004160 A004161 A004162 * A004164 A004165 A004166

Keyword

nonn,base

Author

N. J. A. Sloane

Extensions

Initial 0 and terms after a(43) from Eric M. Schmidt, Apr 04 2014

Status

approved