The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A078403 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A078403

Primes whose digital root (A038194) is prime.
(history; published version)

#14 by N. J. A. Sloane at Mon Jan 22 06:35:16 EST 2024

STATUS

proposed

approved

#13 by Michel Marcus at Thu Jan 04 01:28:36 EST 2024

STATUS

editing

proposed

#12 by Michel Marcus at Thu Jan 04 01:28:20 EST 2024

NAME

Primes such that whose digital root (A038194) is prime.

CROSSREFS

Cf. A038194, A061238, A061240, A061241, A070027, A078400.

STATUS

proposed

editing

#11 by Ya-Ping Lu at Wed Jan 03 22:59:07 EST 2024

STATUS

editing

proposed

#10 by Ya-Ping Lu at Wed Jan 03 22:58:36 EST 2024

COMMENTS

Union of A061238, A061240, A061241 and 3. - Ya-Ping Lu, Jan 03 2024

PROG

(Python) from sympy import isprime, primerange; [print(p, end = ', ') for p in primerange(2, 570) if isprime(p%9)] # Ya-Ping Lu, Jan 03 2024

CROSSREFS

Cf. A061238, A061240, A061241, A070027, A078400.

STATUS

approved

editing

#9 by Harvey P. Dale at Sun Aug 20 15:22:00 EDT 2017

STATUS

editing

approved

#8 by Harvey P. Dale at Sun Aug 20 15:21:55 EDT 2017

MATHEMATICA

Select[Prime[Range[200]], PrimeQ[Mod[#, 9]]&] (* Harvey P. Dale, Aug 20 2017 *)

STATUS

approved

editing

#7 by Russ Cox at Fri Mar 30 17:36:39 EDT 2012

EXTENSIONS

Extended by Robert G. Wilson v, Klaus Brockhaus and _Rick L. Shepherd (rshepherd2(AT)hotmail.com), _, Dec 27 2002

Discussion

Fri Mar 30

17:36

OEIS Server: https://oeis.org/edit/global/176

#6 by Russ Cox at Fri Mar 30 17:30:51 EDT 2012

EXTENSIONS

Extended by _Robert G. Wilson v (rgwv(AT)rgwv.com), __, _Klaus Brockhaus_ and Rick L. Shepherd (rshepherd2(AT)hotmail.com), Dec 27 2002

Discussion

Fri Mar 30

17:30

OEIS Server: https://oeis.org/edit/global/156

#5 by Russ Cox at Fri Mar 30 17:27:39 EDT 2012

EXTENSIONS

Extended by Robert G. Wilson v (rgwv(AT)rgwv.com), _Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) _ and Rick L. Shepherd (rshepherd2(AT)hotmail.com), Dec 27 2002

Discussion

Fri Mar 30

17:27

OEIS Server: https://oeis.org/edit/global/145