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A297710 Partition numbers (A000041) in which parity of digits alternates. 0
1, 2, 3, 5, 7, 30, 56, 101, 385, 490, 3010, 4565, 8349, 10143 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

No more terms up to numbpart(7000).

Intersection of A000041 and A030141.

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

8349 is in the sequence because 8, 3, 4 and 9 have even and odd parity alternately.

PROG

(PARI)

is_alt(n) = m=n; e=n%10; n\=10; while(n>0, f=n%10; if(e%2==f%2, return, e=f; n\=10)); return(m)

select(is_alt, vector(7000, n, numbpart(n)))

(Python)

from sympy import npartitions

A297710_list = []

for i in range(1, 10**6):

    n = npartitions(i)

    s = [int(d) for d in str(n)]

    for j in range(len(s)-1):

        if not (s[j]+s[j+1]) % 2:

            break

    else:

        A297710_list.append(n) # Chai Wah Wu, Jan 04 2018

CROSSREFS

Cf. A000041, A030141.

Sequence in context: A269022 A174536 A054797 * A287945 A238850 A245064

Adjacent sequences:  A297707 A297708 A297709 * A297711 A297712 A297713

KEYWORD

nonn,base,more

AUTHOR

Colin Barker, Jan 04 2018

STATUS

approved

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Last modified January 17 19:58 EST 2019. Contains 319251 sequences. (Running on oeis4.)