A116327
k times k+8 gives the concatenation of two numbers m and m+5.
Original entry on oeis.org
79, 35475530, 41357883, 58642110, 64524463, 3317813164402425001808, 3762581663871761671881, 4019782237714250566387, 4464550737183587236460, 5535449262816412763533, 5980217762285749433606, 6237418336128238328112
Offset: 1
64524463 * 64524471 = 41634068//41634073, where // denotes concatenation, so 64524463 is a term.
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from itertools import count, islice
from sympy import sqrt_mod
def A116327_gen(): # generator of terms
for j in count(0):
b = 10**j
a = b*10+1
for k in sorted(sqrt_mod(21,a,all_roots=True)):
if a*(b-5) <= k**2-21 < a*(a-6) and k>4:
yield k-4
A116327_list = list(islice(A116327_gen(),20)) # Chai Wah Wu, Feb 21 2024
A116197
Numbers k such that k concatenated with k+5 gives the product of two numbers which differ by 9.
Original entry on oeis.org
25, 2448207281, 2552334847, 9492271895, 10713024775597019390267617, 45251510049471045364918031, 99414584492459886818648287, 1000584180267191789271991959007645
Offset: 1
A116321
n times n+9 gives the concatenation of two numbers m and m+4.
Original entry on oeis.org
36, 56, 35161, 64831, 80616, 3987149564, 4383189168, 5616810824, 6012850428, 7706615964, 8102655568, 4345867705884192320, 4745041385024898581, 5254958614975101411, 5654132294115807672, 79423444003688998051750982
Offset: 1
A116334
n times n+9 gives the concatenation of two numbers m and m+6.
Original entry on oeis.org
45, 47, 3180, 3454, 6538, 6812, 32423077888994073533, 47028976905526474404, 49049512306209075907, 50950487693790924085, 52971023094473525588, 67576922111005926459, 71498432899270376140, 75216895567882908524
Offset: 1
6812 * 6821 = 4646//4652, where // denotes concatenation.
Showing 1-4 of 4 results.