OFFSET
1,2
COMMENTS
Zeroless analog of the positive pentagonal numbers.
LINKS
Paolo Xausa, Table of n, a(n) for n = 1..10000
MATHEMATICA
noz[n_] := FromDigits[DeleteCases[IntegerDigits[n], 0]];
Block[{n = 1}, NestList[noz[++n*3 - 2 + #] &, 1, 100]]
PROG
(PARI) noz(n) = fromdigits(select(sign, digits(n))); \\ A004719
lista(nn) = my(va=vector(nn)); for (n=1, nn, va[n] = if (n==1, 1, noz(va[n-1] + 3*n - 2))); va; \\ Michel Marcus, Jun 03 2024
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Paolo Xausa, May 28 2024
STATUS
approved