A304480 a(n) is the least m such that lambda(k) >= n for all k >= m where lambda is A002322, the Carmichael lambda function.

1, 3, 25, 25, 241, 241, 505, 505, 505, 505, 505, 505, 65521, 65521, 65521, 65521, 65521, 65521, 65521, 65521, 65521, 65521, 65521, 65521, 131041, 131041, 131041, 131041, 131041, 131041, 171865, 171865, 171865, 171865, 171865, 171865, 138181681, 138181681, 138181681, 138181681, 138181681, 138181681

Offset: 1

Author

Michel Marcus, May 13 2018

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..5000
• Project Euler, Problem 533 - Minimum values of the Carmichael function
• Wikipedia, Carmichael function

Crossrefs

Cf. A002174, A002322, A002396, A141162, A143407, A335116, A335117.

Programs

PARI

minvl(n, v) = {vgt = select(x->(x>=n), v, 1); first = vgt[1]; vgtd = vector(#vgt-1, k, vgt[k+1] - vgt[k]); vgtdr = Vecrev(vgtd); vokdiff = select(x->x!=1, vgtdr, 1); if (#vokdiff, #v - vokdiff[1]+1, first);}
lista(nn) = {v = read("v002322.txt"); for (n=1, nn, print1(minvl(n, v), ", "););}

Extensions

a(32) and beyond from Seiichi Manyama, May 24 2020