



1, 4, 2, 7, 7, 3, 10, 12, 10, 4, 13, 17, 17, 13, 5, 16, 22, 24, 22, 16, 6, 19, 27, 31, 31, 27, 19, 7, 22, 32, 38, 40, 38, 32, 22, 8, 25, 37, 45, 49, 49, 45, 37, 25, 9, 28, 42, 52, 58, 60, 58, 52, 42, 28, 10
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OFFSET

1,2


COMMENTS

Row sums = A084990: (1, 6, 17, 36, 65, 106, ...).
A128225 = A127899(unsigned) * A004736.


LINKS

Table of n, a(n) for n=1..55.


FORMULA

A004736 * A127899 (unsigned). By columns, (3k+1), (5k+2), (7k+3),...; k=0,1,2...


EXAMPLE

First few row of the triangle are:
1;
4, 2;
7, 7, 3;
10, 12, 10, 4;
13, 17, 17, 13, 5;
16, 22, 24, 22, 16, 6;
19, 27, 31, 31, 27, 19, 7;
...


MATHEMATICA

(* a127899U computes the unsigned version of A127899 *)
a127899U[n_, k_] := If[n==kn1==k, n, 0]/; (1<=k<=n)
a004736[n_, k_] := nk+1/; (1<=k<=n+1)
a128225[n_, k_] := a127899U[n, n](a004736[n, k] + a004736[n1, k])/; (1<=k<=n)
a128225[r_] := Table[a128225[n, k], {n, 1, r}, {k, 1, n}]
TableForm[a128225[7]] (* triangle *)
Flatten[a128225[10]] (* data *) (* Hartmut F. W. Hoft, Mar 13 2017 *)


CROSSREFS

Cf. A004736, A084990, A127899, A128225.
Sequence in context: A237750 A249652 A110841 * A049817 A203575 A120871
Adjacent sequences: A128223 A128224 A128225 * A128227 A128228 A128229


KEYWORD

nonn,tabl


AUTHOR

Gary W. Adamson, Feb 19 2007


STATUS

approved



