

A249034


Odd numbers missing from A171947.


4



5, 13, 17, 21, 29, 37, 45, 49, 53, 61, 65, 69, 77, 81, 85, 93, 101, 109, 113, 117, 125, 133, 141, 145, 149, 157, 165, 173, 177, 181, 189, 193, 197, 205, 209, 213, 221, 229, 237, 241, 245, 253, 257, 261, 269, 273, 277, 285, 293, 301, 305, 309, 317, 321, 325
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OFFSET

1,1


COMMENTS

These are the odd terms in A171946.
Consider the sequence of first differences, divided by 4: 2, 1, 1, 2, 2, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 2, 2, 1, 1, 2, 2, 2, ... This is, almost certainly, A026465 without its leading 1.  N. J. A. Sloane, Oct 30 2014
This sequence appears to be the same as A260191, Numbers n such that there exists no square whose basen digit sum is binomial(n,2), without that sequence's leading 3.  Jon E. Schoenfield, Jul 19 2015


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000


MATHEMATICA

f[n_] := Block[{a = {1}, b = {}, k}, Do[k = 2; While[MemberQ[a, k]  MemberQ[b, k], k++]; AppendTo[a, 2 k  1]; AppendTo[b, k], {i, 2, n}]; a]; Complement[Range[1, Max@ #, 2], #] &@ f@ 120 (* Michael De Vlieger, Jul 20 2015 *)


PROG

(Haskell)
a249034 n = a249034_list !! (n1)
a249034_list = filter odd a171946_list
 Reinhard Zumkeller, Oct 26 2014


CROSSREFS

Cf. A026465, A171946, A171947, A260191.
Sequence in context: A039955 A213340 A014539 * A208883 A182078 A074278
Adjacent sequences: A249031 A249032 A249033 * A249035 A249036 A249037


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Oct 26 2014


STATUS

approved



