A080824 Numbers k such that T(k) = T(A072522(k)) + T(A072522(k+1)), T(i) being the triangular numbers.

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

Links

Chai Wah Wu, Table of n, a(n) for n = 1..2400

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

Adjacent sequences: A080821 A080822 A080823 * A080825 A080826 A080827

Keyword

nonn

Author

Ralf Stephan, Mar 27 2003

Status

approved