A072522 Smallest number a(n)>a(n-1) such that T(a(n-1))+T(a(n))=T(m) for some m, a(1)=3; T(i) are the triangular numbers.

3, 5, 6, 9, 13, 44, 58, 854, 896, 1194, 1253, 1469, 1628, 2170, 2403, 3205, 3366, 3395, 4370, 4454, 4676, 6234, 6545, 6873, 9165, 9624, 12833, 17110, 17450, 18524, 24012, 25025, 25652, 28242, 37657, 356750, 400894, 420938, 561250, 1347002

Offset

1,1

Links

Chai Wah Wu, Table of n, a(n) for n = 1..2401

Prog

(PARI) p=3; print1("3, "); for(n=2, 50, t=p*(p+1)/2; for(k=p, 10^9, u=t+k*(k+1)/2; v=floor(sqrt(2*u)); if(v*(v+1)/2==u, print1(k", "); p=k; break)))

Crossrefs

Cf. A072521, A082183. Values of m are in A080824.

Sequence in context: A039873 A096394 A075472 * A294909 A070111 A070117

Adjacent sequences: A072519 A072520 A072521 * A072523 A072524 A072525

Keyword

nonn

Author

Amarnath Murthy, Jul 31 2002

Extensions

Edited by Ralf Stephan, Mar 27 2003

Status

approved