A180052 Partial sums of A180039.

1, 113, 111336, 1111333670, 111113333667115, 111111333336667111671, 1111111333333666671111667338, 111111113333333666667111116667334116, 111111111333333336666667111111666673334112005, 1111111111333333333666666671111111666667333341112001005

Offset

1,2

Comments

Row 5 of the Pascal array expressed as triangular numbers in 2 ways (value and number of digits). Could be viewed as part of a group expressing the n-th row of the Pascal array in n ways (see example).

Links

Table of n, a(n) for n=1..10.

Example

For the fifth row of the Pascal array, n=5:
1,5,15,..
1,14,150,..
1,113,111336,..
1,1112,1111112223,..
1,11111,111111111111111,..
For n=4:
1,4,10,20,..
1,13,136,1370,..
1,112,111223,1111222334,..
1,1111,1111111111,11111111111111111111,..

Mathematica

Accumulate[Accumulate[Table[FromDigits[PadRight[{}, n, 1]], {n, Accumulate[ Range[10]]}]]] (* Harvey P. Dale, Jun 12 2021 *)

Crossrefs

Cf. A007318, A052262, A180039.

Sequence in context: A352400 A329105 A304324 * A106748 A220983 A122503

Adjacent sequences: A180049 A180050 A180051 * A180053 A180054 A180055

Keyword

nonn

Author

Mark Dols, Aug 08 2010

Status

approved