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A156297
Triangle T(n,k) read by rows. If n = k^2 then 1 else 0.
1
1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
OFFSET
1,1
COMMENTS
Triangle can be used as an operator.
EXAMPLE
Table begins:
1;
0,0;
0,0,0;
0,1,0,0;
0,0,0,0,0;
0,0,0,0,0,0;
0,0,0,0,0,0,0;
0,0,0,0,0,0,0,0;
0,0,1,0,0,0,0,0,0;
0,0,0,0,0,0,0,0,0,0;
0,0,0,0,0,0,0,0,0,0,0;
0,0,0,0,0,0,0,0,0,0,0,0;
0,0,0,0,0,0,0,0,0,0,0,0,0;
0,0,0,0,0,0,0,0,0,0,0,0,0,0;
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0;
0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0;
PROG
(PARI)
up_to = 97461; \\ binomial(441+1, 2), 441 = 21^2
A156297tr(n, k) = ((k*k) == n);
A156297list(up_to) = { my(v = vector(up_to), i=0); for(n=1, oo, for(k=1, n, i++; if(i > up_to, return(v)); v[i] = A156297tr(n, k))); (v); };
v156297 = A156297list(up_to);
A156297(n) = v156297[n]; \\ Antti Karttunen, Dec 24 2018
CROSSREFS
Sequence in context: A354037 A185118 A240332 * A373483 A373372 A373143
KEYWORD
nonn,tabl
AUTHOR
Mats Granvik, Feb 07 2009
STATUS
approved