

A158086


Number of occurrences of n as an entry in rows <= 2n of Losanitsch's triangle (A034851).


0



4, 4, 5, 4, 6, 4, 4, 6, 5, 4, 6, 4, 4, 4, 6, 4, 4, 6, 6, 4, 4, 4, 4, 6, 4, 4, 6, 4, 6, 4, 4, 4, 4, 4, 6, 4, 5, 4, 4, 4, 6, 4, 6, 4, 4, 4, 4, 6, 4
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OFFSET

2,1


COMMENTS

For n = 1 to 1000, the only values of a(n) are 4, 5, 6, 8, 10 and infinity.


LINKS

Table of n, a(n) for n=2..50.


EXAMPLE

a(4) = 5 because 4 occurs five times in Losanitsch's triangle: the first time at row 4, column 2, being the sum of the two 2's in the row above; and at column 1 of rows 7 and 8, which are symmetrically duplicated at row 7, column 6 and row 8, column 7.


MATHEMATICA

(* The following assumes a[n, k] has already been defined to give Losanitsch's triangle; see for example the program given for A153046 *)
tallyLozOccs[1] := Infinity; tallyLozOccs[n_Integer?Positive] := Module[{i, searchMax, tally}, i = 0; searchMax = 2n; tally = 0; While[i <= searchMax, tally = tally + Length[Select[Table[a[i, m], {m, 0, i}], # == n &]]; i++ ]; Return[tally]]; Table[tallyLozOccs[n], {n, 2, 50}]
(* this program also assumes a(n, k) has been defined for Losanitsch's triangle*)
Table[Length[Select[Flatten[Table[a[i, m], {i, 0, 2n}, {m, 0, i}]], #==n&]], {n, 2, 50}] (* Wilfredo Lopez (chakotay147138274(AT)yahoo.com), Mar 18 2009 *)


CROSSREFS

Cf. A003016, Number of occurrences of n as an entry in rows <= n of Pascal's triangle.
Sequence in context: A046593 A158935 A226446 * A195783 A167770 A080800
Adjacent sequences: A158083 A158084 A158085 * A158087 A158088 A158089


KEYWORD

easy,nonn


AUTHOR

Alonso del Arte, Mar 12 2009


STATUS

approved



