A107263 Position where n (presumably) appears the last time in A032531, or 0 if n keeps appearing.

20678, 95695, 120724, 133876, 1148205

Offset

0,1

Comments

The sequence resulted from analysis of A032531(n), n<= 2*10^6.

We can only speak of provisional values and, in the absence of any proof, I am not sure how rigorous these results are for n > 2*10^6. - Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 03 2006

I extended the analysis of A032531(n) to all n<= 10^7. Same comments apply considering the new limit and, of course, the uniqueness of Stephan's sequence remains as always only a conjecture since there's no proof that the sequence should be anything different from the zero sequence for all, most or even any of the terms - Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 08 2006

Links

Table of n, a(n) for n=0..4.

Prog

(PARI) b(n)=n-binomial(floor(1/2+sqrt(2+2*n)), 2) value=vector(400000); posit=vector(400000); for(i=0, 10000000, value[value[b(i)+1]+1]+=1; posit[value[b(i)+1]+1]=i); for(k=1, 5, print1(posit[k], ", ")) - Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 08 2006

Crossrefs

Cf. A107262.

Sequence in context: A173378 A028519 A247926 * A372296 A237329 A292021

Adjacent sequences: A107260 A107261 A107262 * A107264 A107265 A107266

Keyword

nonn,hard,more

Author

Ralf Stephan, May 15 2005

Extensions

Corrected and extended by Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 03 2006, Nov 08 2006

Status

approved