A116102
Numbers k such that k concatenated with k-8 gives the product of two numbers which differ by 2.
Original entry on oeis.org
16, 1337032, 2084503, 2953232, 4023943, 1330033613070195328, 4036108433661798551, 8283744867954114232, 6247320195351414276186411625291, 9452080202814205132771066881607
Offset: 1
4023943//4023935 = 6343455 * 6343457, where // denotes
concatenation.
A116226
n times n+2 gives the concatenation of two numbers m and m-9.
Original entry on oeis.org
4622, 5377, 7980, 34952, 46865, 53134, 65047, 7056186, 9783459, 43176670, 56823329, 97999800, 447255476452, 552744523547, 755424659534, 799319866013, 997999998000, 4297663349523, 5702336650476, 6971253996227
Offset: 1
97999800 * 97999802 = 96039609//96039600, where // denotes
concatenation.
-
A:= NULL: count:= 0:
for d from 2 to 40 do
R:= [msolve(x^2=-8,10^d+1)];
T:= sort(select(t -> t*(t+2) mod 10^d >= 10^(d-1), map(t -> subs(t,x-1),R)));
count:= count+nops(T);
A:= A, op(T);
od:
A; # Robert Israel, Jan 04 2021
A116096
Numbers k such that k concatenated with k-9 gives the product of two numbers which differ by 4.
Original entry on oeis.org
21, 30, 902406, 959721, 6040059046, 6242406405, 9842410005, 9900249006, 15033519988494, 17250863148969, 22499666270469, 27632040031654, 34182546327286, 37487353123861, 52213551379230, 74230108225630
Offset: 1
9900249006//9900248997 = 9949999499 * 9949999503, where // denotes concatenation.
A116094
Numbers k such that k concatenated with k-9 gives the product of two numbers which differ by 1.
Original entry on oeis.org
15, 771, 939, 2099721, 2935179, 5235841, 5424812334857206131, 6846608332924813315, 1458115445754267551129074204621, 3821059872421656136462055529015, 5557540612916539470512122318065
Offset: 1
5235841//5235832 = 7235911 * 7235912, where // denotes
concatenation.
Showing 1-4 of 4 results.