OFFSET
0,2
COMMENTS
Subsequence of A002113. - Chai Wah Wu, Jul 30 2025
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..999
David Applegate, Marc LeBrun and N. J. A. Sloane, Carryless Arithmetic (I): The Mod 10 Version
FORMULA
a(n)=Sum[Mod[Binomial[n, m], 10]*10^m, {m, 0, n}]. - Roger L. Bagula and Gary W. Adamson, Sep 14 2008
EXAMPLE
a(7)=17155171 since a(6)=1650561 and digits of a(7) are sum mod 10 of 1, 6+1=7, 5+6=1, 0+5=5, 5+0=5, 6+5=1, 1+6=7 and 1.
MATHEMATICA
Table[Sum[Mod[Binomial[n, m], 10]*10^m, {m, 0, n}], {n, 0, 30}] (* Roger L. Bagula and Gary W. Adamson, Sep 14 2008 *)
PROG
(PARI) a(n) = fromdigits(Vec(Pol(digits(11))^n)%10); \\ Seiichi Manyama, Mar 10 2023
(Python)
from math import comb, prod
from sympy.ntheory.modular import crt
from gmpy2 import digits
def A059734(n):
k, l = 0, len(s:=digits(n, 5))
for m in range(n+1):
t = digits(m, 5).zfill(l)
k = 10*k+crt([5, 2], [prod(comb(int(s[i]), int(t[i]))%5 for i in range(l))%5, int(not ~n & m)])[0]
return k # Chai Wah Wu, Jul 30 2025
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Henry Bottomley, Feb 20 2001
STATUS
approved
