

A157502


Even numbers without the squares.


4



2, 6, 8, 10, 12, 14, 18, 20, 22, 24, 26, 28, 30, 32, 34, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130
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OFFSET

1,1


COMMENTS

Complement of A128201.


LINKS

Table of n, a(n) for n=1..60.


FORMULA

Set R(n) = round(sqrt(2*n)), then a(n) = 2*n + R(n)  (R(n) mod 2).


EXAMPLE

a(2) = 6 as the next even after 2, i.e., 4 (a perfect square), drops out and is replaced by following even.


PROG

(PARI) isok(n) = ((n % 2) == 0) && ! issquare(n); \\ Michel Marcus, Aug 26 2013


CROSSREFS

Cf. A088828, A128201, A157512.
Cf. A000290 (squares), A005843 (even numbers).
Sequence in context: A005795 A319827 A327905 * A216032 A076300 A049637
Adjacent sequences: A157499 A157500 A157501 * A157503 A157504 A157505


KEYWORD

nonn


AUTHOR

Gerald Hillier, Mar 01 2009


EXTENSIONS

More terms from Michel Marcus, Aug 26 2013


STATUS

approved



