A338977 Primes p*A007953(p)+1 for p in A338976.

5, 23, 53, 137, 191, 827, 569, 1553, 857, 1091, 2087, 2339, 1811, 3347, 2711, 5867, 3449, 10979, 7127, 5231, 8753, 7883, 6131, 6311, 11057, 11633, 8111, 13649, 18899, 19661, 10091, 10631, 17393, 11171, 9209, 16703, 17207, 19727, 19979, 29741, 31181, 34739, 12809, 38699, 25523, 26783, 39461, 28547

Offset

1,1

Comments

All terms == 5 (mod 6).

Terms are not in numerical order.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(3) = 53 = 13*(1+3)+1 where 13 and 53 are prime.

Maple

A:= select(t -> isprime(t) and isprime(t*convert(convert(t, base, 10), `+`)+1), [$2..10^4]):
map(t -> t*convert(convert(t, base, 10), `+`)+1, A);

Prog

(PARI) f(p) = p*sumdigits(p)+1;
isok(p) = isprime(f(p));
apply(f, select(isok, primes(300))) \\ Michel Marcus, Dec 19 2020

Crossrefs

Cf. A007953, A338976.

Sequence in context: A140811 A247657 A241099 * A090686 A082277 A289154

Adjacent sequences: A338974 A338975 A338976 * A338978 A338979 A338980

Keyword

nonn,look

Author

J. M. Bergot and Robert Israel, Dec 18 2020

Status

approved