A258877 Primes p=prime(m) such that both p and m have the same digital root.

97, 131, 199, 263, 349, 457, 479, 521, 541, 617, 661, 733, 829, 839, 881, 1039, 1049, 1091, 1103, 1277, 1289, 1301, 1361, 1433, 1487, 1499, 1549, 1571, 1759, 1913, 1933, 1993, 2089, 2099, 2129, 2141, 2221, 2273, 2357, 2377, 2389, 2441

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Formula

a(n) = A000040(A258876(n)).

Example

Both 97 = prime(25) and 25 have digital root = 7,
both 131 = prime(32) and 32 have digital root = 5.

Mathematica

Reap[Do[If[FixedPoint[Total[IntegerDigits[#]]&, n]==Mod[(p=Prime[n]), 9], Sow[p]], {n, 439}]][[2, 1]]
Prime[Select[Range@370, Mod[#, 9]==Mod[Prime[#], 9]&]] (* Ivan N. Ianakiev, Jun 18 2015 *)

Crossrefs

Cf. A000040, A010888, A038194, A258876.

Sequence in context: A234101 A161367 A216311 * A073076 A157213 A000923

Adjacent sequences: A258874 A258875 A258876 * A258878 A258879 A258880

Keyword

nonn,base

Author

Zak Seidov, Jun 13 2015

Status

approved