A190646 - cp's OEIS frontend

A190646 Least number k such that d(k-1) = d(k+1) = 2n or 0 if no such k exists, where d(n)=A000005(n).

n	a(n)
1	4
2	7
3	19
4	41
5	127252
6	199
7	26890624
8	919
9	17299
10	6641
11	25269208984376
12	3401
13	3900566650390624
14	640063
15	8418574
16	18089
17	1164385682220458984374
18	41651
19	69528379848480224609374
20	128465
21	34084859374
22	12164095
23	150509919493198394775390626
24	90271

[4, 7, 19, 41, 127252, 199, 26890624, 919, 17299, 6641, 25269208984376, 3401, 3900566650390624, 640063, 8418574, 18089, 1164385682220458984374, 41651, 69528379848480224609374, 128465, 34084859374, 12164095, 150509919493198394775390626, 90271]

cp's OEIS Frontend

A190646 Least number k such that d(k-1) = d(k+1) = 2n or 0 if no such k exists, where d(n)=A000005(n).

Table of values

List of values