A116099
Numbers k such that k concatenated with k-9 gives the product of two numbers which differ by 7.
Original entry on oeis.org
69, 59898667, 79493157, 13412927190959690154913903, 14163000698458955079906403, 38895475965785687555173929, 40165600438484442828161229, 74294440818366638194239027
Offset: 1
79493157//79493154 = 89158933 * 89158938, where // denotes concatenation.
79493157//79493158 = 89158934 * 89158937.
79493157//79493160 = 89158935 * 89158936.
79493157//79493148 = 89158932 * 89158939.
A116301
n times n+1 gives the concatenation of two numbers m and m+2.
Original entry on oeis.org
768, 859, 911, 3286, 6714, 45453, 54547, 990101, 8181820, 70588234, 343130555, 362637364, 363636362, 420053632, 421052633, 497975710, 502024290, 578947367, 579946368, 636363638, 637362636, 656869445, 706766919
Offset: 1
-
As:= {}:
for m from 2 to 20 do
acands:= map(t -> rhs(op(t)), [msolve(a*(a+1)=2, 10^m+1)]);
bcands:= map(t -> t*(t+1) mod 10^m, acands);
good:= select(t -> bcands[t]>=10^(m-1), [$1..nops(acands)]);
As:= As union convert(acands[good],set);
od:
sort(convert(As,list)); # Robert Israel, Aug 20 2019
A116308
Numbers k such that k*(k+2) is the concatenation of two numbers m and m+3.
Original entry on oeis.org
452, 547, 690, 855, 4381, 5618, 72729, 346532, 653467, 9090907, 94117645, 334665332, 336032386, 378253327, 390977441, 439928490, 483516485, 516483514, 560071509, 609022558, 621746672, 663967613, 665334667
Offset: 1
A116314
Numbers k such that k*(k+1) gives the concatenation of two numbers m and m+4.
Original entry on oeis.org
28, 72, 79822845, 69852478553064869297984899963807, 77473062193002372448027740546439, 77747359197583788609974143907619, 84341826458653210947638195982115, 85367942837521291760016984490251
Offset: 1
79822845 * 79822846 = 63716866//63716870, where // denotes concatenation.
Showing 1-4 of 4 results.
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