A342836 a(n) is the smallest prime factor of A342834(n).

7, 797, 3, 7, 37, 3023681, 43, 1249, 7, 3, 23, 11, 3, 19, 3, 13390093693131976661567, 193, 2069, 11, 41, 3, 71, 3, 996370591, 3, 101, 1123, 54367, 159469, 151, 29, 3, 7

Offset

1,1

Comments

a(n) = A342834(n) for n = 1 and n = 2, no other solution is known.

No primes through a(258). - Michael S. Branicky, Mar 25 2021

a(34) <= 7944676315964871787139677901. a(35)..a(40) = 2089, 11, 3, 23, 3, 11. a(42)=3. - Chai Wah Wu, Mar 26 2021

Links

Table of n, a(n) for n=1..33.

Chai Wah Wu, terms a(44)..a(84)

Formula

a(n) = A020639(A342834(n)).

Example

As A342834(5) = 7||97||997||9973||99991 = 797997997399991 = 37 * 951649 * 22663307, then a(5) = 37.

Crossrefs

Cf. A020639, A338968, A342834, A342835.

Sequence in context: A171245 A014013 A001467 * A338968 A342834 A278438

Adjacent sequences: A342833 A342834 A342835 * A342837 A342838 A342839

Keyword

nonn,base,more

Author

Bernard Schott, Mar 24 2021

Extensions

a(4)-a(14) from Daniel Suteu, Mar 24 2021

a(15)-a(33) from Michael S. Branicky and Apurva Rai, Mar 25 2021

Status

approved