The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A060288 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A060288

Distinct (non-overlapping) twin Harshad numbers whose sum is prime.
(history; published version)

#18 by Bruno Berselli at Tue Jan 19 05:49:01 EST 2021

STATUS

reviewed

approved

#17 by Joerg Arndt at Tue Jan 19 04:03:08 EST 2021

STATUS

proposed

reviewed

#16 by Joerg Arndt at Tue Jan 19 04:03:04 EST 2021

STATUS

editing

proposed

#15 by Joerg Arndt at Tue Jan 19 04:02:59 EST 2021

CROSSREFS

Cf. A005349, A060159, A060289, A060290, A060291.

STATUS

proposed

editing

#14 by Michel Marcus at Tue Jan 19 02:02:01 EST 2021

STATUS

editing

proposed

#13 by Michel Marcus at Tue Jan 19 02:01:56 EST 2021

LINKS

Carlos Rivera, <a href="https://www.primepuzzles.net/puzzles/puzz_129.htm">Puzzle 129. Earliest sets of K consecutive Harshad Numbers</a>, The Prime Puzzles and Problems Connection.

STATUS

proposed

editing

#12 by Amiram Eldar at Tue Jan 19 01:48:25 EST 2021

STATUS

editing

proposed

#11 by Amiram Eldar at Tue Jan 19 01:38:03 EST 2021

LINKS

Amiram Eldar, <a href="/A060288/b060288.txt">Table of n, a(n) for n = 1..10000</a>

#10 by Amiram Eldar at Tue Jan 19 01:37:46 EST 2021

COMMENTS

Suggested by Puzzle 129, The Prime Puzzles and Problems Connection.

LINKS

Carlos Rivera, <a href="https://www.primepuzzles.net/puzzles/puzz_129.htm">Puzzle 129</a>, The Prime Puzzles and Problems Connection.

MATHEMATICA

harshadQ[n_] := Divisible[n, Plus @@ IntegerDigits[n]]; s = {}; q1 = True; Do[q2 = harshadQ[n]; If[q1 && q2, If[PrimeQ[2*n - 1], AppendTo[s, 2*n - 1]]; q1 = False, q1 = q2], {n, 2, 5000}]; s (* Amiram Eldar, Jan 19 2021 *)

CROSSREFS

A005349, A060159, A060289 etc, A060290, A060291.

#9 by Amiram Eldar at Tue Jan 19 01:36:43 EST 2021

OFFSET

0,1,1

EXTENSIONS

Offset corrected by Amiram Eldar, Jan 19 2021

STATUS

approved

editing