A343128 Numbers k such that prime(prime(prime(k))) ends in k.

7, 229, 417, 657, 26203, 32553, 50971, 93487, 231221, 17064941, 54784601, 93007099, 981668491, 16040988367

Offset

1,1

Links

Table of n, a(n) for n=1..14.

Example

417 is a term since prime(prime(prime(417))) = 302417.
26203 is a term since prime(prime(prime(26203))) = 73226203.
17064941 is a term since prime(prime(prime(17064941))) = 169217064941.
prime(prime(prime(54784601))) = 647454784601, prime(prime(prime(93007099))) = 1185993007099, prime(prime(prime(981668491))) = 17148981668491, prime(prime(prime(16040988367))) = 390416040988367. - Chai Wah Wu, Apr 14 2021

Prog

(Python)
A343128_list = [n for n in range(1, 10**4) if n % 2 and n % 5 and prime(prime(prime(n))) % 10**(len(str(n))) == n]

Crossrefs

Cf. A046883, A074978.

Sequence in context: A157693 A221029 A221495 * A142116 A201955 A081618

Adjacent sequences: A343125 A343126 A343127 * A343129 A343130 A343131

Keyword

nonn,base,more

Author

Chai Wah Wu, Apr 06 2021

Extensions

a(11)-a(14) from Chai Wah Wu, Apr 14 2021

Status

approved