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A079823 Consider the triangle shown below; sequence contains the concatenation of numbers read at a 45-degree angle upwards with horizontal beginning with the first term of a row. 2
1, 2, 43, 75, 1186, 16129, 22171310, 29231814, 3730241915, 4638312520, 564739322621, 675748403327, 79685849413428, 92806959504235, 10693817060514336, 121107948271615244, 137122108958372625345, 1541381231099684736354, 1721551391241109785746455 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
16 17 18 19 20 21
...
a(n) also is the concatenation of the terms of the n-th row of A056536. - Michel Marcus, Dec 14 2023
LINKS
MAPLE
read("transforms"):
A079823aux := proc(n, k)
A000124(n)+k ;
end proc:
A079823 := proc(n)
local L, k, n0 ;
n0 := n-1 ;
L := [] ;
for k from 0 do
if k > n0-k then
break;
end if;
L := [op(L), A079823aux(n0-k, k)] ;
end do:
digcatL(L) ;
end proc: # R. J. Mathar, Aug 23 2012
# second Maple program:
T:= (i, j)-> i*(i-1)/2+j:
a:= n-> parse(cat(seq(T(n-j, j+1), j=0..(n-1)/2))):
seq(a(n), n=1..23); # Alois P. Heinz, Aug 03 2022
MATHEMATICA
Table[FromDigits[Join@@IntegerDigits[Table[Binomial[n-k+1, 2] + k, {k, Ceiling[n/2]}]]], {n, 30}] (* G. C. Greubel, Dec 13 2023 *)
CROSSREFS
Sequence in context: A137415 A090194 A107200 * A107156 A062582 A073594
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Feb 11 2003
EXTENSIONS
More terms from Jason D. W. Taff (jtaff(AT)jburroughs.org), Oct 31 2003
Corrected by Philippe Deléham, Feb 16 2004
STATUS
approved

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Last modified February 22 06:21 EST 2024. Contains 370240 sequences. (Running on oeis4.)