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A080824
Numbers k such that T(k) = T(A072522(k)) + T(A072522(k+1)), T(i) being the triangular numbers.
3
6, 8, 11, 16, 46, 73, 856, 1238, 1493, 1731, 1931, 2193, 2713, 3238, 4006, 4648, 4781, 5534, 6240, 6458, 7793, 9039, 9491, 11456, 13290, 16041, 21388, 24439, 25449, 30327, 34682, 35837, 38153, 47071, 358732, 536644, 581296, 701563, 1459252, 2169403, 2527162, 2644637
OFFSET
1,1
PROG
(PARI) p=3; for(n=2, 50, t=p*(p+1)/2; for(k=p, 10^9, u=t+k*(k+1)/2; v=sqrtint(2*u); if(v*(v+1)/2==u, print1(v", "); p=k; break)))
CROSSREFS
Cf. A072522.
Sequence in context: A020937 A183208 A048586 * A183979 A100602 A222175
KEYWORD
nonn
AUTHOR
Ralf Stephan, Mar 27 2003
STATUS
approved