A128373 - OEIS

%I #7 Aug 26 2022 16:53:19

%S 4,7,8,11,13,16,19,12,22,26,29,34,37,43,46,53,17,18,56,64,67,76,79,89,

%T 92,103,106,118,23,25,121,134,137,151,154,169,172,188,191,208,24,211,

%U 229,30,33,232,251,254,274,277,298,301,323,326,349,352,376,379,404,38

%N Irregular triangle read by rows: row n (n>=2) lists positions in the sequence A007318 where n appears.

%e In A007318, the number 2 appears in position 4, so the first row is 4. The number 3 appears in positions 7 and 8 in A007318, so the second row is 7, 8.

%e The irregular triangle begins:

%e    4

%e    7,  8

%e   11, 13

%e   16, 19

%e   12, 22, 26

%e   29, 34

%e   37, 43

%e   46, 53

%e   ...

%Y Cf. A003015, A003016, A007318, A059233.

%K easy,nonn,tabf

%O 2,1

%A _Nick Hobson_, Mar 01 2007