The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A199983 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A199983

Primes whose multiplicative digital root is 4.
(history; published version)

#15 by Charles R Greathouse IV at Sun Aug 03 14:01:36 EDT 2014

MATHEMATICA

t = {}; n = 0; While[Length[t] < 100, n = NextPrime[n]; s = n; While[s >= 10, s = Times @@ IntegerDigits[s]]; If[s == 4, AppendTo[t, n]]]; t (* _T. D. Noe, _, Nov 16 2011 *)

Discussion

Sun Aug 03

14:01

OEIS Server: https://oeis.org/edit/global/2267

#14 by Charles R Greathouse IV at Mon May 13 01:49:59 EDT 2013

COMMENTS

Can this sequence be proved to be infinite? [_Charles R Greathouse IV, _, Nov 13 2011]

Discussion

Mon May 13

01:49

OEIS Server: https://oeis.org/edit/global/1914

#13 by Russ Cox at Fri Mar 30 19:00:25 EDT 2012

AUTHOR

_Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), _, Nov 13 2011

Discussion

Fri Mar 30

19:00

OEIS Server: https://oeis.org/edit/global/299

#12 by N. J. A. Sloane at Sun Dec 18 13:40:04 EST 2011

STATUS

editing

approved

#11 by N. J. A. Sloane at Sun Dec 18 13:40:01 EST 2011

COMMENTS

Can this sequence be proven proved to be infinite? [Charles R Greathouse IV, Nov 13 2011]

STATUS

approved

editing

#10 by T. D. Noe at Wed Nov 16 13:04:32 EST 2011

STATUS

editing

approved

#9 by T. D. Noe at Wed Nov 16 13:04:28 EST 2011

DATA

41, 89, 127, 139, 193, 271, 277, 379, 383, 397, 463, 643, 677, 727, 739, 937, 1193, 1217, 1249, 1277, 1319, 1429, 1721, 1913, 1931, 1973, 2377, 2711, 3119, 3191, 3313, 3331, 3373, 3461, 3719, 3727, 3733, 3911, 3917, 4111, 4129, 4219, 6143, 7121, 7127, 7193

MATHEMATICA

t = {}; n = 0; While[Length[t] < 100, n = NextPrime[n]; s = n; While[s >= 10, s = Times @@ IntegerDigits[s]]; If[s == 4, AppendTo[t, n]]]; t (* T. D. Noe, Nov 16 2011 *)

CROSSREFS

Cf. A199984 (composite numbers whose multiplicative digital root is 4). A034051 (numbers whose multiplicative digital root is 4).

Cf. A034051 (numbers whose multiplicative digital root is 4).

STATUS

proposed

editing

#8 by Jaroslav Krizek at Wed Nov 16 03:15:37 EST 2011

STATUS

editing

proposed

#7 by Jaroslav Krizek at Wed Nov 16 03:15:31 EST 2011

DATA

41, 89, 127, 139, 193, 271, 277, 379, 383, 397, 463, 643, 677, 727, 739, 937, 1193, 1217, 1249, 1277, 1319, 1429, 1721, 1913, 1931, 1973, 2377, 2711, 3119, 3191, 3313, 3331, 3373, 3461, 3719, 3727

CROSSREFS

Cf. A199984 (composite numbers whose multiplicative digital root is 4). A034051 (numbers whose multiplicative digital root is 4).

#6 by T. D. Noe at Mon Nov 14 01:18:11 EST 2011

KEYWORD

nonn,changed,base

STATUS

proposed

editing