A255772 Start with 7; thereafter, in order of appearance, the prime factors of A220294.

7, 3, 13, 241, 97, 673, 193, 22253377, 18446744069414584321, 769, 442499826945303593556473164314770689, 349621839326921795694385454593, 331192380488114152600457428497953408512758882817, 212780015855109121

Offset: 1

Author

Hans Havermann, Mar 06 2015

Keywords

• nonn

Comments

A220161(n-1) = the product of the first A255770(n) terms.

References

• Arthur Engel, Problem-Solving Strategies, Springer, 1998, pages 121-122 (E3, said to be a "recent competition problem from the former USSR").

Links

• Hans Havermann, Table of n, a(n) for n = 1..22
• factordb, First 20 factorizations of A220294

Crossrefs

Cf. A220161, A220294, A255770, A255771.