A079132 -id:A079132 - cp's OEIS frontend

A079130 Primes such that iterated sum-of-digits (A038194) is a square.

13, 19, 31, 37, 67, 73, 103, 109, 127, 139, 157, 163, 181, 193, 199, 211, 229, 271, 283, 307, 337, 373, 379, 397, 409, 433, 463, 487, 499, 523, 541, 571, 577, 607, 613, 631, 643, 661, 733, 739, 751, 757, 769, 787, 811, 823, 829, 859, 877, 883, 919, 937, 967

Offset: 1

Klaus Brockhaus, Dec 28 2002

Primes which are 1 or 4 mod 9. - Charles R Greathouse IV, Sep 04 2014

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Cf. A078403, A079131, A079132.

select(isprime,map(t -> (9*t+1,9*t+4),[$1..1000]));  # Robert Israel, Sep 04 2014

sQ[n_]:=MemberQ[{1,4,9},NestWhile[Total[IntegerDigits[#]]&,n,#>9&]]; Select[Prime[Range[300]],sQ] (* Harvey P. Dale, Dec 06 2012 *)

forprime(p=2,1000,if(issquare(p%9),print1(p,",")))

a(n) ~ 3n log n. - Charles R Greathouse IV, Sep 04 2014

A079131 Primes such that iterated sum-of-digits (A038194) is odd.

Original entry on oeis.org

3, 5, 7, 19, 23, 37, 41, 43, 59, 61, 73, 79, 97, 109, 113, 127, 131, 149, 151, 163, 167, 181, 199, 223, 239, 241, 257, 271, 277, 293, 307, 311, 313, 331, 347, 349, 367, 379, 383, 397, 401, 419, 421, 433, 439, 457, 487, 491, 509, 523, 541, 547, 563, 577, 599

Offset: 1

Klaus Brockhaus, Dec 28 2002

Subsequence of primes of A187318. - Michel Marcus, Jun 08 2015

Primes congruent to 1, 3, 5, 7 mod 18. - Robert Israel, Jun 08 2015

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

Cf. A038194, A078403, A079130, A079132, A187318.

[p: p in PrimesUpTo(600) | p mod 18 in [1,3,5,7]]; // Vincenzo Librandi, Jun 07 2015

[a: n in [0..1000] | IsPrime(a) where a is Floor(9*n/5)]; // Vincenzo Librandi, Jun 08 2015

select(isprime, [3, seq(seq(i*18+j, j=[1,5,7]),i=0..100)]); # Robert Israel, Jun 08 2015

Select[Prime[Range[120]], OddQ[Mod[#, 9]] &] (* Bruno Berselli, Aug 31 2012 *)

forprime(p=2,600,if((p%9)%2==1,print1(p,",")))

cp's OEIS Frontend

A079130 Primes such that iterated sum-of-digits (A038194) is a square.

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