A254100 Postludic numbers: Second column of Ludic array A255127.

4, 9, 19, 31, 55, 73, 101, 145, 167, 205, 253, 293, 317, 355, 413, 473, 521, 569, 623, 677, 737, 763, 833, 917, 983, 1027, 1051, 1121, 1171, 1273, 1337, 1411, 1471, 1571, 1619, 1663, 1681, 1807, 1957, 1991, 2087, 2113, 2171, 2245, 2275, 2335, 2401, 2497, 2593, 2713, 2771, 2831, 2977, 3047, 3113

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..10001

Formula

a(n) = A255407(A001248(n)).

Mathematica

rows = 100; cols = 2; t = Range[2, 10^4]; r = {1}; n = 1; While[n <= rows, k = First[t]; AppendTo[r, k]; t0 = t; t = Drop[t, {1, -1, k}]; ro[n++] = Complement[t0, t][[1 ;; cols]]]; A = Array[ro, rows]; Table[A[[n, 2]], {n, 1, rows} ] (* Jean-François Alcover, Mar 14 2016, after Ray Chandler *)

Prog

(Scheme) (define (A254100 n) (A255127bi n 2)) ;; A255127bi given in A255127.

Crossrefs

Column 2 of A255127. (Row 2 of A255129). Positions of 2's in A260739.

Subsequence of A192607, A302036 and A302038.

Cf. A276576, A276606 (first differences).

Cf. also A001248, A219178.

Sequence in context: A180784 A015618 A086733 * A365801 A008239 A038403

Adjacent sequences: A254097 A254098 A254099 * A254101 A254102 A254103

Keyword

nonn

Author

Antti Karttunen, Feb 22 2015

Status

approved